Glossary of Lapidary and Jewelry Making Terms

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

- - A - -

a jour

An open setting that leaves the pavilion facets of a cut gemstone open to the light

abrasive

Hard, tough material used to smooth out rough surfaces; a common abrasive is sandpaper.

accessory mineral

Mineral that occurs with other minerals.

aigrette

Refers to the tufted crest, or head-plumes of the egret, used for adorning a woman's head-dress and to an ornament, such as a spray of gems, resembling a tuft of plumes. Often worn in the hair or on a cap.

alloy

A metal that is manufactured by combining two or more molten metals. An alloy is always harder than its component metals. Common alloys used in jewelry are: gold under 24 Kt (mixed with silver, copper, and/or other metals), sterling silver (92.5% silver, 7.5% copper), brass (roughly half copper, half zinc), bronze (at least 60% copper with tin and perhaps other metals), and pewter (tin, lead, antimony, and a bit of silver or copper).

alpaca / alpacca

An alloy consisting of mostly copper (roughly 60 percent), and approximately 20 percent nickel, about 20 percent zinc, and about 5 percent tin. This metal is a a silver substitute.

amalgam

Any alloy of mercury and another metal. Some amalgams occur naturally. Note: There is a mineral known as Amalgam, and, although it is an amalgam, should not be confused with the term amalgam.

amber

The fossilized resin of prehistoric pine trees which ranges in color from golden to orange-red

amorphous

Without a crystalline shape. An amorphous gem, like amber, or ivory, does not have a regular internal structure, like those gems that fall within the seven crystal systems.

anisotropic

Lacking consistent hardness on all surfaces. For example, the hardness of Kyanite on the Mohs scale is between 6 and 7 lengthwise, and between 4 and 4½ crosswise

ankle bracelet, ankle chain, anklet

An ornament worn around the ankle.

anneal

The process of heating metal for a period of time to release the molecular changes created when it has been hardened either through work hardening or heat hardening. In jewelry making the heating is usually until the metal is red hot.

anodized

Metal put through an electrochemical process which changes the molecular structure of the surface layer, giving it a thin, protective film. In the anodization process, the metal is placed in an acid bath (at the "anode" or positive end of the electrical circuit) and an electrical current is passed through the tank. This process causes a controlled oxidation of the metal's surface to occur (oxygen atoms bond to surface atoms of the metal). Aluminum is often anodized, as is magnesium, titanium, and tantalum. Anodized metal has a lustrous sheen; the anodizing process can produce colorful surfaces.

antique cushion cut

A gem shape similar to an octagon, but with all curved sides around the girdle.

appraisal

An individual's opinion as to the value of an item. This value can established for market value, replacement value, or insurance purposes. Usually each successive value class is somewhat higher than the previous listed category value.

arabesque

A form of decoration characterized by flowing lines, scrollwork, leaves, branches, floral forms, symmetrical in form.

arborescent

Synonym to dendritic: Aggregate composed of skeletal or tree-like formations. May be a single entity, or a formation that forms from mineral-rich solutions that deposit the mineral in rock and form a tree or plant structure embedded in rock. There sometimes is a distinction noted between the two aggregates; in some guides the former aggregate (single entity) is known as skeletal, and the latter as dendritic (embedded in rock). Other guides, such as this one, don't distinguish the two, and term them both as dendritic.

arcade setting

Also called coronet or châton setting, is one in which the stone is held in by many metal claws around a metal ring.

argos gold

Term used for any inferior quality jewelry. It is not necessarily bought from the United Kingdom retailer Argos, but view as low cost and flashy.

arm ring

A band of usually precious metal worn as an ornament around the biceps of the upper arm. Also called armlet or an armband.

art deco

A style popular from the mid-1920's until the 1930's. This style originated in Paris, France. Pieces are characterized by geometric lines and angles, with very few curves. This art movement eventually became bolder and evolved into Art Moderne.

art nouveau

A style popular from roughly 1895 until World War I. Pieces are characterized by curves and naturalistic designs, especially depicting long-haired, sensual women. Louis Comfort Tiffany made archetypal Art Nouveau pieces.

arts and crafts

An artistic movement that produced hand-crafted pieces toward the end of the 1800's. Pieces purposely look hand-made, incorporating hammer marks and simple cabochon settings. The Arts and Crafts movement also revived the art of enamel.

assay

The process that determines the proportions of precious metal contained in a piece of gold or silver. Meat used in jewelry making may display an assay hallmark identifying assayer.

asterism

Effect exhibited on some minerals (usually only in polished cabochons) causing it to reflect a billowy, star-like formation of concentrated light which moves around when the mineral is rotated. Asterism is caused by dense inclusions of tiny, parallel, slender, fibers in the mineral which cause the light to reflect in such an interesting manner. Minerals that display asterism may exhibit four, six, and sometimes twelve rayed "stars", depending on the inclusions, size, and facet mode. Some specimens may display much stronger asterism than others, and some specimens may have areas where the inclusions are not present, leaving holes or empty areas in the star.

asymmetrical

Not containing perfect symmetry.

auriferous

Containing gold.

axis

Imaginary line drawn through the center of an object, either horizontally or vertically. In the case of minerals, it is used to determine if and how mineral has symmetry. The horizontal axis is known as the x axis, the vertical axis as the y axis. Axis lines are usually drawn as dotted lines. Plural is axes.

axis of symmetry

An imaginary line drawn through the center of a crystal that replicates the exact shape if the crystal is turned to 360°. Minerals can have symmetry on their x axis (horizontal symmetry), on their y axis (vertical symmetry), and both their x and y axes. Symmetry can also be calculated on degrees, which depends on how often a crystal must be rotated to bring out symmetry (i.e. a hexagon has six-fold symmetry on a 60° angle)

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- - B - -

bail

The portion of a pendent through which the chain or necklace passes.

baguette

A gemstone cut in the shape of a narrow rectangle. Baguette means "stick" or "rod" in French.

bakelite

The trade name for the first synthesized plastic invented by Dr. Leo Backeland. It was the first plastic made from synthetic components (phenol and formaldehyde, generally with a wood flour filler) and was used in diverse products such as kitchenware, pipe stems, toys, and jewelry.

band

A ring that is made from a thin, flat, ribbon-like strip of material, usually metal. The band can be unadorned or decorated.

bangle

A bracelet variety designed to slip over the hand which moves around freely on the wrist. Often, several are worn at once so that they make noise when they bang together.

bar and ring clasp

Also called a toggle clasp is a jewelry fastener in which a bar can be inserted into a ring to fasten a piece of jewelry. It is used to attach the two ends of a necklace or bracelet.

barraco / baroque

Ancient Portuguese noun for a pearl that is an unpredictable or elaborate shape. Freshwater pearls are most commonly baroque but there are artificial versions. The term evolved into Baroque meaning elaborate and with may details.

barrel clasp

A jewelry fastener that resembles a barrel. The two pieces of this clasp screw together. It is used to attach two other rings or links of a necklace or bracelet.

basal

Having to do with the base.

basal cleavage

Type of cleavage exhibited on a horizontal plane of a mineral by way of its base. Minerals with basal cleavage can sometimes be "peeled", like minerals of Mica group.

basse-taille

French for ‘shallow cut’. This is an enameling technique worked in a chased relief metal and overlaid with translucent enamel.

baton

A baton is a stone that is cut in a long, thin rectangular shape. A baton is larger than a baguette.

bell cap

A jewelry finding that is used to convert a hole-less bead or stone with into a pendant. A bell cap is glued onto the bead or stone and had a loop for attaching to the piece of jewelry.

bezel

1. The part of a cut stone that protrudes above the edge of a setting. The bezel is also known as the crown.
2. A style of stone setting in which a strip of metal completely encloses the outer edge of the stone securing it in place.

bib necklace

Also known as a collarette, is a short necklace with flowing ornaments in the front.

birefringence

Another name for double refraction where the light entering the stone is split into two light rays, and the rays travel in different paths.

birthstone

Gems assigned to different birth months, originally based on astrology. Many different lists exist today. You can view several at birthstones

bolt ring

A circular catch used for the fastening of necklaces or bracelet chains. It is a hollow or partly hollow connecting ring drawn back on a spring.

bort

Term for industrial grade diamonds.

boule

Synthetic gems created from molten liquids placed in tear shaped molds to crystallize, leaving them with a tear-like form. Mostly applied to synthetic Rubies and Sapphires.

bracelet

Any article of jewelry worn around the wrist.

brass

Man-made alloy of (at least 50%) copper and zinc. Originally any alloy of copper was known as brass and early brass was commonly an alloy of copper and tin. See also bronze. This alloy naturally oxidizes green.

brazilian chain

Also called a snake chain, it is a metal chain made up of a series of small, linked cups.

brilliant

1. Referring to cut: A type of cut used for certain gemstones, frequently diamonds. It has 56 facets, 32 facets are above the girdle, 24 are below and is also called a full or modern cut.
2. Referring to luster: Synonym of adamantine.

briolette

A teardrop shaped stone faceted with triangular or rectangular facets. May also be called a ‘drop-cut’

brooch

A decorative jewelry item designed to be attached to garments. It is usually made of metal like silver, gold, bronze or some other material. They are often decorated with enamel or gemstones. They may be solely for ornament or serve a practical function like a fastener for a garment.

bronze

"Bronze" is a collective term describing any metallic alloy that range in color from light yellow to orange. Many, if not most alloys described as "bronze" are of copper (at least 60%) and tin. Used since ancient times for coinage, sculpture, weapons as well as jewelry. This alloy oxidizes in various manners depending upon environment it is exposed to.

buff top cabochon

A cabochon where the pavilion is faceted and the top remains a smooth dome. (see cabochon below)

bulla

An ancient Roman pendant that consists of a rounded container holding an amulet (good luck charm) worn on a strap around the neck.  ^top

- - C  - -

cabochon

A gem or stone that has been cut into a shape with a flat bottom and has a highly polished, rounded , smooth dome top. (See our How To Cab online guide)

calibre-cut

Small stones usually cut in rectangular shapes and faceted in a step cut to fit exactly into a setting or against another stone.

calipers

Any of various measuring instruments having two usually adjustable arms, legs, or jaws used especially for fine measuring diameter or thickness.

cameo

Gem with a design or figure carved out of the stone, and raised above the background layer

carat

Weight measurement used in reference to gemstones in regard to their evaluation. A carat is .2 grams (or 200 milligrams), and this weight is used worldwide, even in the U.S. where the metric system isn't used. A point is the weight used only in reference to very small, precious gemstones, and represents 1/100th of a carat. The abbreviation for carat is Ct. and for point is Pt. The term carat in regard to gemstones should not be confused with the term carat in regard to gold. By gold, it refers to the content of gold a gold ornament contains. Because of the confusion, the term carat in regard to gold has been changed to karat.

carving

carving Ornamental figure, such as a stone lion, carved out of a rock or mineral. A piece of stone formed this way is described as carved.

casting

Filling a mold with molten metal to produce a form. Some metals can be poured into a mold, while others need to be forced into it through various methods such as spin casting, vacuum casting, or steam casting.

cats eye

A mineral with dense inclusions of tiny, parallel, slender, fibers that may cause it to exhibit chatoyancy. The most notable cat's eye mineral is Chrysoberyl Cat's Eye, which is known simply as Cat's Eye. Other cat's eye minerals are termed by their respective names, such as a cat's eye Quartz is known as "Quartz Cat's Eye".

channel setting

A style of setting used for faceted stones in which channels are created in parallel strips, where the girdles of stones will fit. Creates a clean line of stones.

chasing

Technique of working a design into a metal from the front using a hammer and/or punches.

chatelaine

A girdle or belt from which various implements are suspended.

chatoyancy

Phenomenon of certain cat's eye minerals which causes it to exhibit a concentrated narrow band of reflected light across the center of the mineral. Chatoyancy is usually only seen on polished cabochons. Chatoyant is the ability to exhibit chatoyancy.

choker

A a tight-fitting necklace, worn high on the neck. It can consist of one or more bands circling the neck.

claw

A metal prong that holds a stone securely in a setting.

claw setting

Setting in which a series of metal prongs, claws, holds a stone securely in a setting by gripping the the stone just above the girdle. There is no metal directly under the stone making it an open setting letting light in under the stone. Usually used for transparent, faceted stones. The modern-day claw setting became popular in the 1800's.

clarity

Term used in grading colored gems or diamonds to describe the level of internal inclusions, fractures or stress marks inside of the stone. Colored stone are assess with the naked eye, diamonds are graded under 10 power magnification.

cleavage

The property some minerals have of tending to split along clean planes in one or more directions. Not all minerals posses cleavage and many can be cleaved in several different directions. Cleavage is related to the minerals crystalline structure. (see mineral properties)

cleavage angle

The angle, or side, that exhibits or has exhibited cleavage.

collet

Round band or flange of metal encircling a gemstone to hold it in place.

color

Measurement scale used in describing the level of tint in the body color of a diamond. "D" color represents the absence of color, and is the most desired. Tint levels progress through the alphabet as color levels increase.

critical angle

The minimum angle at which a stone's pavilion facets can be cut to allow the light entering a gem to be reflected back out of the stone's crown, making the gem brilliant, instead of windowed. The proper critical angle varies, depending on a gem's refractive index.

cross facet

Small triangular facets above and below the girdle of a brilliant cut stone.

crown

The upper portion of a faceted stone from the girdle up to the top of the stone.

crystal

A mineral in which the systematic internal arrangement of atoms is outwardly reflected as a latticework of repeated three-dimensional units that form a geometric solid with a surface consisting of symmetrical planes. (see mineral properties)

crystalline

1) Having a crystal structure.
2) Composed of visible crystals.

ct.

Abbreviation for carat

cut

1. n A description of the type of facet. Used to describe the quality of faceting evenness, diameter to depth proportions, and diameter to table proportions of a polished gem.
2. v Meaning faceted. Differentiates a faceted and polished stone from an unworked crystal.

cymophone effect

Phenomenon seen on a few polished gems that cause it to exhibit a floating light reflection that moves as the gem is rotated. ^top

- - D - -

damascening

The inlaying of a soft metal like silver or copper into a hard metal like steel. The name comes from the city of Damascus, where this process was first used.

dead stone

A foil-backed rhinestone that has lost its original shininess, usually after water has damaged the foil. For example, a "dead" clear rhinestone will appear dull and off-white, greenish or yellowish.

dead soft

Refers to very soft-tempered metal. For example, copper electrical wire is dead soft.

demillune

Meaning "half moon", it is stone is shaped like a half moon.

demi-parure

A matching set of jewelry, usually containing a necklace, earrings, and a pin.

dentelle

Rhinestones cut with 32 or 64 facets.

diadem

A semi circular band worn around the head (tiara). It is usually jeweled and three dimensional.

diamonté

Another word for rhinestone.

dichroic / dichroism

The property of having more than one color, especially when viewed from different angles. Many minerals are naturally dichroic. This effect can be artificially caused by a thin layer of a metallic oxides that is deposited on the surface of a material. Dichroic coated glass transmits some wavelengths of light and reflecting others, giving it an opal-like appearance.

die stamping

A process in which sheet metal is cut and shaped between two dies, forming a pattern in relief. Two steel dies are used, the male die has the design in cameo (protruding); the female die has the design hollowed out. The male die is put on top of the metal, the female die is put on the underside of the metal. The press is forcefully brought down onto the dies and metal, forcing the metal into the shape of the mold.

diffusion treated

Refers to process where stones are color-enhanced . This process only colors the outer surface of the stone, so chipping or re-polishing will result in a loss of color. Diffusion-treated stones are already-cut stones that are heated in the presence of other compounds (like iron oxide, chromium oxide, titanium dioxide, etc.) that will infuse the extreme outer surface stone with color. Under a microscope, you you can see the loss of color within each tiny scratch. Diffusion treatment can also change the stone's refractive index. Also, if the stone is faceted, the color will appear stronger where the facets meet.

diffraction

The bending of light when it enters from one medium into another. For example, light bends as it travels from air into another substance, such as water. Diffraction also occurs when light enters from the air into a mineral, and the amount of diffraction varies among minerals.

dispersion

The splitting of white light into the colors of the spectrum. When white light enters a crystal, it splits up; some rays are reflected and some are absorbed, forming the mineral's color. Gemstones are cut in a fashion that the split-up light in the crystal fans out its colors and reflects from an exact face. This causes "fire" in a gem, which is best seen on colorless gems.

divitrification

Changing over from a natural glass to a mineral with a crystalline structure. To devitrify is the process of a natural glass to lose its glassy nature and crystallize.

dog collar

A type of short, multiple-strand choker-style necklace that fits tightly against the neck. Dog collars are also known as " plaque de cou" (meaning "neck badge") when they are fastened by a clasp in the front. Dog collars are 14"-15" in length.

double refractive

The ability of some gems to split a ray of light into two separate rays, each traveling at a different velocity. This effect caused the pavilion faceting to appear doubled when the stones is viewed through the table.

doublet

A gem made from two layers in order to save expenses; the lower part of the composite stone is glass or a non-precious stone, the top is the more valuable stone. One common doublet contains a layer of real garnet and a layer of glass.

dopping wax

A hard wax used to attach the dop stick to the stone to be cut.

dop stick

A small stick or dowel on which stones are mounted temporarily so they can be secured for cutting. Sometimes just called a dop.

drop cut

A pear-shaped cut gemstone with triangular facets on top. Also called briolette, is a common form for a pendant.

druze

A layer of crystals that form within a mineral crust, like the inner cavity of a geode.

ductile

Substances easily pulled or stretched into a thin wire. Gold is the most ductile metal. ^top

- - E - -

EGL

Acronym for European Gemological Laboratory

electroplating

A method (also called Galvanotechnics after its inventor, Luigi Galvani) in which an electric current deposits a layer of metal on an object. For example gold electroplated over a less expensive base metal. The thickness of the metal coat varies. Electrogilded coating is the thinnest (less than 0.000007 inches thick); gold-cased metals have a coating thicker that 0.000007 inches.

 

electrum

An amber-colored alloy of gold and silver that was used in ancient times. Electrum is also an alloy used in medieval times consisting of copper (50%), nickel (30%) and zinc (20%).

emboss

A method of surface decoration in which a design is raised slightly above the surface. Sheets of metal, leather, and plastic can be embossed.

emerald cut

Rectangular shaped stone with mitered corners which is elongated and octagonal.

enamel

Process of fusing powdered colored glass and metal oxides to a surface by means of high heat like a kiln.

engraving

Inscribing metal or other materials using a sharp blade sometimes called a scriber or a tool known as a “graver” to form a design. Can be done by either hand or machine.

enhanced

Enhanced stones are stones that have been treated to improve their color, clarity, finish, strength, or other characteristics. Some common enhancements are heat-treatment, irradiation, coating the surface, filling cracks, oiling, surface diffusion (coating the surface then applying heat), bleaching, dyeing, etc.

etching

Removal of part of a metal surface by acid for a decorative effect.

eternity ring

A narrow ring with gemstones set all around it.

etui

Also called a necessaire, is a tiny, decorative, cylindrical-shaped case that was often carried on a chatelaine. The etui was used to carry small "necessary" items like pencils, scissors, manicure set, or spectacles. The etui was first used in the 1720's.

european cut

Also known as the old European cut, is an old, round diamond cut that is similar to but less bright than the newer brilliant cut. The European cut has a very small table and heavy crown.

eyepin

A thin wire with a loop at one end; it is used for linking beads together. ^top

- - F - -

face

1) An individual flat section of a faceted gem.
2) Crystal face.

facet

A smooth polished face surface on a cut gemstone.

faceted stone

A stone that has been precisely cut into angular planes to facilitate the scattering and return of light to the viewer's eye.

fancy cut

Are stones are cut in unusual ways. Some fancy cuts include the heart, fan, rivoli, trapezium, cathedral window, half-moon (lunette), kite, and triangle.

fancy diamond

Fancy diamonds are rare diamonds that are red, blue, green, or purple; these diamonds are quite valuable.

fantasy cut

Is a new way of faceting stones that uses freeform angles - virtually anything goes.

faux

Means false; a faux gem is an imitation.

feather

Is an internal flaw (also called an inclusion) in a gemstone that can start at the surface of the stone and extend deep inside. Feathers can either ruin a stone (by making it fragile and/or changing the color), or add to its beauty.

fede ring

A three part ring, the Fede ring depicted two hands and a heart. When all 3 rings were joined, the hands clasped over the heart. The Claddagh ring is a version of the Fede ring.

fetish

A charm, amulet, pendant or other decoration associated with magical properties; it often represents an animal or person.

fibula

A brooch / pin hat looks a bit like a safety pin. Fibulas have been used since ancient times to secure clothing.

figural

Jewelry designed to look like real objects. Common subjects are the human body, animal, insects, shells, flowers, leaves, and everyday objects like baskets and fans.

filigree

Wire, usually gold or silver, twisted and shaped into designs. It may be soldered to a sheet of metal or twisted to form an openwork pattern.

findings

The parts that jewelers use in making jewelry. For example, clasps, hooks, pin backs, jump rings, and earring backs are findings.

fineness

The proportion of silver or gold in a metal alloy. Fineness is usually expressed in parts per thousand. For example, the fineness of sterling silver is 925.

flaw

An imperfection in a gemstone such as cracks, inclusions of other minerals or liquid-filled cavities. A flawless stone is called "clean." Flaws can greatly reduce the value of a stone, but in some cases, like moss agate or rutilated quartz, the "flaws" increase the value of the stone.

floater necklace

Also called invisible, looks as though the beads are simply floating on the skin; the beads or pearls are strung far apart from one another on an almost invisible string material.

flux

A substance applied to metal prior to brazing or soldering which cleans the metal and creates a coating on the surface to protect it from re-oxidizing during the process.

flux fusion

A high temperature method of growing some varieties of synthetic gemstones.

fob

A small charm, trinket or other object that hangs on a watch chain, girdle, or belt (chatelaine).

foiling

A thin sheet of metal applied to the base of a stone that is put in a closed setting. Done to enhance the color of a gemstone.

fold over clasp

A jewelry fastener that is composed of a device that opens and closes with a hinge, and latches shut. It is used to attach the two ends of a necklace or bracelet.

fracture

1. (n) A crack or break in a rock.
2. (v) To break in random places instead of cleaving.
3. The characteristic way a mineral breaks when put under stress, aside from cleavage. Said of minerals.

french jet

Black glass (pyrolusite glass) designed to imitate real jet. It was frequently carved.

fresh water pearl

Pearls found in fresh water mussels.

full cut

A gemstone with 58 facets.

furnace glass

Is made by shaping hot glass that was heated in a glass furnace, by hand. Long tubes of glass are drawn from molten glass, then beads are cut from the tube. They are then tumbled and reheated to smooth the edges of the beads. Furnace glass beads are made in a wide variety of colors, shapes, and designs.

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- - G - -

gallery

A strip on metal with a pattern. Term usually refers to the sides of a ring.

gem

A cut mineral or pearl refined for use as an ornament.

gemology

The science and procedures involved in mining, faceting, and marketing of gemstones. A person studying in this discipline is a gemologist.

gemstone

Any mineral or naturally occurring substance in an raw, uncut state that is capable of being a gem.

geode

Hollow rock that is filled or partially filled with crystals.

gerlots

Long, small pendant beads.

german silver

Slso know as nickel silver, is an alloy consisting of mostly copper (roughly 60 percent), and approximately 20 percent nickel, about 20 percent zinc, and sometimes about 5 percent tin (then the alloy is called alpaca). There is no silver at all in German silver. This alloy was invented around 1860 in Germany as a silver substitute.

GIA

Acronym for the Gemological Institute of America. A training facility for gemologists, and a source used to identify or grade various gems.

gilding

The process of covering a base material with a thin layer of metal, often precious like gold or silver.

gimmel ring

A ring formed of two or more linked hoops, which fit together in a manner that make them appear as one ring. Often referred to as puzzle rings. The most popular Gimmel ring, the Fede ring,  depicted two hands and a heart. When all 3 rings were joined, the hands clasped over the heart. The Claddagh ring is a version of the Fede ring.

gipsy or gypsy setting

A recessed setting in which the stone is sunk into the metal. There are often engraved designs around the stone (especially star patterns). This type of setting was developed in the late 1800's and was often used for rings. The gipsy setting is also known as the "star setting."

girandole

Kind of earring or brooch in which three pearls, stones or pendants hang from a large stone. The central drop is usually larger than the other pendants.

girdle

The outermost edge of a faceted stone which divides the crown from the pavilion.

glove ring

A clip-like device used to attach gloves to a purse or other object. It has a clip on one end for the gloves and a chain with a clasp on the other end that attaches to a purse handle.

glyptography

The art of engraving gemstones, making intaglio and cameos. Stones are engraved using grindstones with powdered emory or diamond as an abrasive.

gold

A precious metal that is very soft when pure (24 Kt.). Gold is the most malleable and ductile metal.  It is often mixed (alloyed) with other metals, usually silver and copper to make it less expensive and harder. The purity of gold jewelry is measured in karats. Some countries hallmark gold with a three-digit number that indicates the parts per thousand of gold. In this system, "750" means 750/1000 gold (equal to 18K); "500" means 500/1000 gold (equal to 12K). Alloyed gold comes in many colors.

gold dore

A bar of semi-purified gold (e.g. bullion). After being mined, the first stage in the purification process of the gold ore produces this cast bar that is approximately 90% gold.

gold filled

Abbreviated G.F. or written as "doublé d'or", is jewelry is made of a thin outer layer of gold atop a base metal.

gold planted

Is a metal has a very thin layer of gold on the surface, usually applied by the process of electroplating. Pieces that are gold plated are often marked G.E.P., gold electroplate, gold plated, or electro-plaqué d'or.

grain

1. Unit of weight. A grain is 0.25 of a carat; there are 480 grains to the Troy ounce which is equal to an Avoirdupois grain. (see conversions)
2. A small spherical bead of metal.

granulation

Decorating a metal surface with metal grains.

green gold

Gold with a high proportion of silver.

green rouge

Is chromium dioxide, which is used to polish precious metals, giving them a luster.

grelot

Small beads that have an elongated, pendant shape.

grey gold

Gold with a high proportion of iron.

gunmetal

An alloy of 90 percent copper and 10 percent tin.

gutta percha

Resin from the Isonandra Gutta tree that was used for making jewelry in the mid-1800's. ^top

- - H - -

hair jewelry

Jewelry containing or composed of locks of hair. This type of jewelry was popular in the mid-1800's as a remembrance of deceased loved ones.

hallmarking

Marks stamped on gold, silver or platinum by assay offices after the metal has been tested and determined to contain the proper amount of precious metals as required by law.

hammered metal

Metals formed, shaped, or decorated by with crater-like depressions made by a metalworker's hammer.

hardening

Making a metal stiffer by working it by bending or hammering. Most metals will change at the molecular level when worked in this manner.

hardness

The degree of resistance of a given mineral to scratching, indicating the strength of the bonds that hold the mineral's atoms together. The hardness of a mineral is measured by rubbing it with substances of known hardness.

heishi

Jewelry made from disk-shaped beads of shell or stone. Each bead begins as a tiny flat piece and a tiny stringing hole is drilled though the fragment. Many of these jagged pieces are strung together tightly on a wire and are then sanded into evenness using a fine-grained sandstone and then sandpaper. The result is a very smooth strand of disk-shaped beads. This is an ancient form of bead-making developed by the Pueblos of North America. (pronounced he-she).

herkimer diamond

Are clear, lustrous, doubly terminated crystals of quartz with a hardness of 7- they are not true diamonds. These brilliant stones are also called "Middleville Diamonds" or "Little Falls Diamonds." This stone is found in Middleville and Little Falls, Herkimer County, New York, USA.

hook & eye clasp

A simple and ancient jewelry fastener that is composed of a hook and a circular piece that the hook can latch onto. It is used to attach the two ends of a necklace or bracelet. ^top

- - I - -

IGI

Acronym for International Gemological Institute

Italian charm bracelet

A series of individual modular links hooked together on a stretchy band to form a single charm bracelet. A typical Italian charm bracelet is comprised of eighteen charm links where each link features an design or image soldered onto the actual link.

immersion test

Test done by dropping a stone into a container of a known density liquid to determine a stones density. A stone semi-floats in a liquid that is of a density similar to its own.

inclusion

An internal flaw within a stone. Often inclusions are small mineral crystals

ingot

A precious metal formed into a bar or brick by pouring molten metal into a mold.

inlay

Materials such as stones, gems, woods and metals are inserted and cemented into the surface of another material and ground down to create a smooth surface.

intaglio

Carving or engraving a design into a gemstone. It is the opposite of a cameo which has high relief.

intarsia

Decorative technique in which various types of stone and gem pieces of different color and equal thickness are cut to the shape according to the design and then attached to a support.

investment

A powder of plaster and silica used to create molds for casting. Also the process of creating such a mold.

invisible setting

A channel setting using calibrated stones without any metal showing from the top.

iridescence

Light effect causing a mineral to display a play of colors on an apparently monocolored surface. Iridescence is many times the result of pearly luster, seen around an area where pressure occurred, displaying a similar image to that of fresh oil rising to the surface of a road at the beginning of a rain. Iridescence is also the result of mild tarnishing of a few metallic lustered minerals, such as Chalcopyrite and Hematite.

iridium

A rare earth metal often alloyed with Platinum for jewelry at either 5 or 10 percent to raise the its hardness.

irradiated diamond

Diamonds that have been exposed to radiation thus changing the diamond's color by changing the crystalline structure of the diamond. The change is permanent. Older radiation treatments involving exposing the stone to radium; newer treatments bombard the stone with atomic particles in a cyclotron. The irradiated stones take on a greenish or an aquamarine hue. Irradiations of diamonds was first done in 1904 by Sir William Crookes, who exposed diamonds to radium, giving them a permanent greenish color; his diamonds are still slightly radioactive (at the level of radium-painted watch). Newer irradiation techniques bombard the crystal with atomic particles in a cyclotron, and then the stone is heated to about 800 degrees Centigrade, producing a stone with very little radioactivity and a permanent color change.

irradiation

The act of being exposed to radiation. Many stones are irradiated in order to enhance their color. Being irradiated changes the crystal structure of the mineral by moving electrons. Irradiation techniques bombard the crystal with high-energy radiation (like gamma rays), producing a stone with very little radioactivity and a change of color. Some color changes caused by Irradiation are permanent, others care unstable and be reversed by heating or exposure to sunlight. For example, colorless topaz changes to a cinnamon brown color after being irradiated with cobalt-60 radiation, but the color fades as the stone is exposed to sunlight. A new method of irradiation changes clear topaz to a brilliant, non-fading blue. ^top

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jabot pin

A jeweled tie pin popular in the 1920’s and 1930’s.

jamb peg

An older method of gem cutting using rudimentary tools. Usually produces poor results, but can potentially rival a fine modern cut stone when done by a master, expert cutter.

jelly belly

A piece of jewelry, usually a pin, that has a clear lucite or glass center.

jet

Fossilized coal, often known as Whitby jet for the area of England where much of it came from,  or black jet. It could be faceted and polished and used for ornamental purposes like other gem stones and minerals.

jewel

A gem, whether cut or uncut, capable of being used as an ornament.

jeweler

Individual whose trade is to buy and sell jewels and gemstones.

jewelry

Articles of personal adornment, like rings, necklaces, bracelets, cuff links, and pins, made from metals, especially gold and silver, stones, glass, plastic, and other materials.

jump ring

A wire circle with a split in it. Often used to attach clasps on chains or to attach ear wires to earrings. ^top

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K or Kt.

Abbreviation of karat.

Karat

Unit of measurement describing the content of gold in an ornament. The karat unit measures the percentage of gold in metallic objects made of gold (mainly jewelry). Since pure gold bends too easily, it is mixed with tougher metals when made into ornaments to form a tougher, although impurer, gold. The karat measurement determines the percentage of gold on a 1 to 24 scale, with 24 karats being pure gold. That means that 14 karat gold is only 14/24 (or 58.33%) gold. Gold with a high karat measurement is undesirable for jewelry because it is soft and bendable, and gold with a low karat measurement is undesirable because of its low gold content [hence lesser value]. The term karat can be confused with the term carat, which is the weight measurement for gemstones. The abbreviation of karat is k. or kt.

keeper ring

A ring used alongside another, more valuable ring to keep it securely on the finger.

keystone

A stone cut the shape of a keystone in an arch. Keystones are usually step cut.

king cut

A modification of the brilliant cut having 86 facets which is used for large diamonds.

knot

A flaw in a gemstone that is at the surface of a gem after polishing making a small raised bump on the finished gemstone. ^top

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labradorescence

Effect which causes dark, metallic-like color shimmers, commonly blue and green, to be displayed on a few minerals. The name is derived from Labradorite, a mineral which is the best example of this effect.

lace brooch

Small brooch usually set with diamonds, worn in the later 19th Century

lamen

A general term for a magical pendant worn round the neck so that it hangs upon the breast over the heart. It is also referred to as an amulet usually with the sign or symbols and names of a specific spirit, angel, or god.

lampwork

Is also called torchwork, are pieces formed from glass canes and tubes that are shaped by hand over a flame. Oil lamps and bellows were originally used, hence the name lampworking. Lampworked glass beads are made in a wide variety of colors, shapes, and designs, including millefiori. Lampworking was invented in the 1700's in Murano, Italy.

lap

A flat, rotating disk used to cut and polish a stone during the faceting process.

lapidary

An individual who facets gemstones as a trade, and the shop of such an individual. Also used in adjective form when relating to gems.

lavaliere

A chain from which an ornament or gemstone hangs in the center.

leaf

Paper-thin sheets of metals. Gold, silver, platinum, and copper are rolled or pounded into metallic leaf which can be applied to surfaces.

lentil cut

A cabochon cut in which the upper and lower portions of the stone are identical.

liver of sulfur

A chemical used to oxidize silver and copper.

lobster claw

A type of chain clasp that looks like a lobster's claw. This type is relatively popular because it is durable and easy to hook.

locket

A jewelry setting or pendant which opens on a hinge revealing an interior that can hold additional items, generally pictures.

lock ring

The name given by archaeologists to a type of jewelry from Bronze Age Europe

lost wax casting

A process of casting that follows these steps:

1. A wax model is made of the intended final piece.
2, With wax sprue wires, it is attached to a wax base.
3. A container (flask) is placed around it, and a plaster of paris type substance, called investment, is poured around it and allowed to set up.
4. The flask is placed in a kiln to burn our the wax, leaving a mold of the intended piece.
5. Hot metal is poured or forced into the empty mold, leaving a duplicate of the original wax.

loupe

Small magnifying lens used to observe certain aspects of a gemstone. Loupes usually have a magnification level of 10x.

lozenge

A step-cut gem with a diamond shape.

luster

1. The reflection of light on a given mineral's surface, classified by intensity and quality.
2. The appearance of a given mineral as characterized by the intensity and quality with which it reflects light. ^top

- - M - -

mabepearl

A cultured blister pearl.

machine stamping

Also known as die-stamping, is a process where sheet metal is cut and shaped between two dies, forming a pattern in relief. Two steel dies are used, the male die has the design in cameo (protruding); the female die has the design hollowed out. The male die is put on top of the metal, the female die is put on the underside of the metal. The press is forcefully brought down onto the dies and metal, forcing the metal into the shape of the mold. Many medallions and mass-produced jewelry findings are made this way.

malleable

Metals easily worked with a hammer or a roller. Gold and sterling silver are very malleable metals.

mandrel

A metal rod used to coil molten glass in order to make a bead.

marcasite

Pyrite that is facetted into rose cuts and set into silver or pewter jewelry.

marquise cut

A stone cut in an oval with pointed ends or a boat-shaped stone.

matinee necklace

A matinee necklace is 22" to 23" long. It should sit at the top of cleavage.

matte finish

A surface finish created by sandblasting or brushing that has a soft dull look.

mélange

Term for mixed diamond sizes weighing more than carat.

mêlée

Classification used in the sorting of diamonds weighing less than .20 carat.

melon bead

A hollow and ribbed bead popular in the Etruscan period and in the 1930’s.

memento mori

Jewel that is a reminder of death.

memorial jewel

Jewel that is made in memory of a loved one, often containing hair from that person and frequently decorated with enamel.

memory wire

A tough, stiff wire that retains its shape. It is often used for necklaces and bracelets.

melting point

The temperature it takes a certain material to change from a solid to liquid state.

metal

Any of a category of electropositive (positively charged) elements or combinations of them in the form of minerals that exhibit a metallic luster, malleability, ductility, and conductivity.

metallic

Having the attributes of a metal. Sometimes can be used to describe a mineral with a metallic luster even though it is not a true metal.

metallic luster

Exhibiting the luster of a metal, which is opaque and reflective. Some minerals exhibit a metallic luster even though they are not true metals.

metallurgy

The science and procedures involved in extracting metals from ore, refining the metals, blending them into alloys, and fashioning useful objects from them. Three forms of metallurgy are hydrometallurgy, electrometallurgy, and pyrometallurgy.

micro mosaic

Mosaic of very small colored glass pieces (tessarae) inlaid in glass or hardstone.

micron

A unit of length equal to 0.001 millimeter

Milanese chain

Chain consisting of interwoven rows of small links forming a mesh.

milk and honey effect

When the apparent coloring of a stone changes from milky to the color of honey as the angle of the light changes. When a light is shined on the stone, one side of the stone is the color of milk and the other is the color of honey. When the light changes direction, the color effect also shifts.

millefiori

Glass ornamentation made from canes of colored glass that are layered, and sliced to form patterns, flowers or mosaic effect.

millegrain

Decorating style creating a fine bead like effect around the edge of a metal collet; popular in the Edwardian and Belle Époque periods.

millesimal fineness

A system of denoting the purity of platinum, gold and silver alloys by parts per thousand of pure metal in the alloy. For example, an alloy containing 75% gold is denoted as "750". The millesimal fineness is usually rounded to a three figure number, particularly where used as a hallmark, and the fineness may vary slightly from the traditional versions of purity.

milling

Process in which wood or metal is cut while it either the material or the tool is spinning. Symmetrical shapes and patterns are cut into the material.

mine cut

Stones have a cushion-shaped girdle. This type of cut was popular in the late 1800's.

mineral

Any naturally occurring, three dimensional, inorganic substance, with a chemical structure that can be exact, or can vary within limits. Elements that occur naturally are also listed as minerals.

mississippi river pearls

Irregularly shaped pearls, usually elongated.

mixed cut

A cut where the style of the facets above and below the girdle are different. A standard mixed cut is brilliant cut above and step cut below.

mizpah ring

A broad gold ring engraved with the word MIZPAH, meaning “I will watch over thee”, popular during the Victorian period.

Mokume-Gane

A Japanese  origin technique where multiple layers of different metals are fused together, and then the resulting sheet is punched and filed to produce interesting patterns.

mosaic

Art consisting of a design made of small pieces of colored stone or glass (tessarea) either attached to a base, inlaid,  or inset into another material.

mother of pearl

1) The iridescent inside of a mollusk shell, which is used as an ornament. Not to be confused with pearl.
2) Exhibiting a luster similar to the inside of a mollusk shell or shirt button. Many mica's exhibit a pearly luster, and some minerals with a pearly luster have an iridescent hue. Some minerals may exhibit a pearly luster on cleavage cracks parallel and below the reflecting surface of a mineral. ^top

- - N - -

nacre

The iridescent inside of a mollusk shell, which is used as an ornament. Not to be confused with pearl.

navette cut

A gemstone shaped like a boat or oval with pointed ends.

necessaire

Another word for etui.

necklace

An article of jewelry which is worn around the neck, frequently formed from a metal chain and often attached to a locket or pendant. They can contain  sometimes contain stones, particularly gems, wood, and/or shells. When worn high on the neck it is referred to as a choker.

negligee

A long necklace that usually terminates in irregular length with tassels or drops

nickel silver

An alloy which usually consists of a mixture of Nickel, Copper, and Zinc. Nickel silver does not contain any silver at all, and it was developed to imitate the color of Silver. Various percentages of the above metals could all be termed Nickel Silver. Also called German Silver.

niello

An inlay technique in which the grooves made in silver or gold are made black in color by the use of a composition of metal sulfides. The entire metal piece is heated in a kiln and the niello alloy fuses with the underlying metal. The object is then polished resulting in an enamel-like effect. Niello has been made at least since the time of ancient Rome. In older pieces, the niello alloy fills an engraved design in metal. In newer pieces, the nilello forms the backround - the niello alloy is simply "painted" onto the metal  a simpler but cheaper and less durable process

noble metals

Refers to gold, platinum, and silver. These are metals that are relatively impervious to chemical action. ^top

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oil of vitriol

Synonym of sulfuric acid

oiled

A process in which a stone is soaked in some type of oil to enhance its luster and hide imperfections. This is frequently done to Emeralds because of their fractured nature.

old mine cut

Refers to a brilliant cut in which the stone is cushion-shaped and has a high crown. Early cutting style used on diamonds. Typically mine cut stones lack symmetry and good proportions.

opal

A semi-precious stone with a rainbow-like iridescence. Defined as three types: opalescent precious opals, yellow-red fire opals, and the common opal.

opalescent

Effect seen in a few minerals, chiefly opal (hence its name) which cause it to exhibit a glimmer of different colors when rotated or seen in different angles. Opalescent describes mineral exhibiting this effect.

open-ended necklace

Has no clasp and is worn by tying the ends together around the neck. Open-ended necklaces usually have ornaments, like beads or tassels, at the ends.

opera necklace

An opera necklace is 30" to 36" long and should sit at the breastbone.

orient

The characteristic sheen of fine natural and cultured pearls.

ormolu

Means "ground gold" in French. It is an alloy of copper, tin and zinc that is used to imitate gold. Ormolu can also be cast bronze or brass that is plated with a gold and mercury amalgam, giving it a gold-like look. Ormolu is used in frames, chandeliers, candlesticks, and furniture ornamentation. It was very popular in Georgian and early Victorian design. Ormulu can now also refer to any gold-like metal used as decoration. Ormolu is also called bronze doré or mosaic gold.

oxidation

A discoloration that forms on the surface of many metals as the molecules bond with atmospheric oxygen. ^top

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padparadschan

Name given to a pinkish-orange color of sapphire.

paillons

Small pieces of metallic foil which are placed underneath enamel work to provide a glow, popular with a number of Arts and Crafts movement jewelers.

palladium

A white precious metal belonging to the platinum group, it weighs a little more than half as much as platinum and sells for half the price.

pampilles

A cascade of pendant stones; popular in Georgian jewelry and meant to look like rain drops.

parure

A suite of matching jewelry usually four or more pieces, a necklace, bracelets, earrings and belt or brooch.

passamenterie

Jewelry inspired by furniture trimmings such as cording

paste

A high content leaded glass which is faceted to imitate diamonds or backed with colored foils to imitate other gemstones. Also known as strass after Frederic Strass who invented this method in the 18th century.

paté de verre

Also known as paste or glass paste. See above.

patina

Discoloration that forms on metals such as silver and bronze but often planned for in the artist’s design, can also be introduced artificially by use of chemicals.

pavé

A method of setting faceted stones to produce the look of being covered completely with stones, in essence paving the surface with stones.

pavilion

The bottom portion of a faceted stone from the girdle of the stone to the bottom point or culet.

pear cut

Also called a drop cut, is teardrop shaped and often used for pendants, drop earrings, rings, and other pieces of jewelry.

penannular brooch

A type of early Celtic jewelry that are circular brooches with a long pin often hinged to the base of the pin. They were used to fasten two pieces of cloth together before buttons were invented. The earliest-known piece is the Hunterston brooch from A.D. 700

pendaloque

A type of pear shaped or tear drop gemstone faceted as a brilliant cut and suspended from a smaller stone which is usually separated by a bow or other motif.

pendant

From Old French, it is a hanging object, generally attached to a necklace or an earring.

pendelique

Lozenge shaped cut frequently used for flawed stones that are often used as pendants.

pewter

Metal alloy that is composed mostly of tin (generally over 90 percent) combined with lead, antimony, bismuth, copper, and/or silver  and where the formulation varies. When polished it has a silvery luster. It is a soft alloy that is worked by casting, hammering, or turning.

pickling

Placing metal to be cleaned into a dilute solution of sulfuric acid.

pierce work

Cutting holes in metal with a jeweler's saw to create intricate patterns. This is sometimes confused with filigree, which is fine wires soldered together to create intricate patterns.

pietra dura

Mosaic of semi-precious stones set into a floral pattern of black marble or onyx, also known as a hardstone mosaic.

pin

Term used interchangeably with brooch and is any ornament that can be pinned to a garment.

princess cut

A relatively new diamond cut created in the 1970’s. The cut is sometimes referred to as a “square modified brilliant,” as it combines the brilliance of a round cut with an overall square or rectangular appearance. Today, the princess cut is the second most popular diamond shape, second only to rounds.

princess necklace

A princess necklace is 18" long. It is between choker and matinee length.

princess plus cut

Also known as “The Brighter Princess Cut,” is was created in 2000 by EFD. It has more facets (100-115) than an ordinary princess cut diamond (58-68) and In addition to having more facets, the angles at which they are placed further differentiates the PrincessPlus diamond from regular princess cuts. These differences enhance the diamond’s brilliance, or sparkle. The diamond is technically referred to as a modified princess cut

pinchbeck

A gold simulant, invented circa 1720 by Christopher Pinchbeck, which is comprised of a mixture of copper and zinc.

pink gold

Also known as rose gold, is gold alloyed with a mix of 90% copper and 10% silver giving it a pink tint.

piqué

Tortoiseshell or horn which is inlaid with mother-of-pearl, silver or gold.

planishing

A hammering process done to give a smoother finish to a piece of metal.

plating

See electroplating.

platinum

A non-corrosive silver white metal, which is heavy and has a high tensile strength.

pleochromism

The property of having more than two colors, especially when viewed from different angles. In pleochroic minerals, a single stone will show many colors.

plique à jour

Back-less enamel that is a bit like stained glass as the enamel work is translucent since the backing of the enamel is absent. Cells of enamel are surrounded by delicate wire. Plique à jour is made by shaping cloisonné wire on a thin sheet of metal or mica. Enamel is fired into the wire cells and after it has melted and cooled, the backing is peeled away and the translucent enamel is left suspended in a supporting framework of cloisonné wire.

porous

Term describing stones that have tiny holes in them. These holes allow water, oils, and other substances to penetrate the stone, frequently changing their appearance over time.

posy ring

A ring engraved with a verse.

pot metal

An inexpensive metal alloy, usually containing lead, sometimes used for inexpensive costume jewelry.

princess cut

A square-cut stone. This fancy cut is relatively new and is also known as a Quadrillion or Squarillion cut.

princess length

Necklace, usually referring to a string of pearls, that is 18" long.

promise ring

A pre-engagement ring, usually with a relatively small stone.

prong set

Stones held securely in a setting by tiny metal claws.

proportions

The ratio of a gem's diameter to its table, and depth. Usually expressed as a percentage.

prystal

Sn imitation crystal made from translucent, phenolic plastic.

Pt.

Abbreviation for platinum.  ^top

- - Q - -

quoit

A type of brooch (often circular) popular during Saxon times. It was affixed with a single, straight, unclasped pin. It is thought to be an evolutionary link between Roman belt devices and the modern belt buckle.

quadrillion cut

A square-cut stone. This fancy cut is relatively new and is also known as a Princess or Squarillion cut.

quartz

One of the most abundant minerals in the Earth's crust, chemical formula is SiO2, forms six-sided crystals and has no cleavage. It has a moh's hardness of 7. It has many varieties including Amethyst, Citrine, Smokey Quartz, Rose Quartz, Chalcedony, and Tiger's eye among others. Chalcedony in particular has many sub-varieties. ^top

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radiant cut

A method of cutting rectangular stones invented in the 1970's so that they have the sparkle of brilliant cut round stones. The shape is a rectangle with the corners clipped off - the length : width ratio is usually from 1.5:1 to 1.75:1. This cut has from 58-70 facets: The top of the stone is emerald cut with about 25 facets above the girdle, but the bottom of the stone has brilliant cut facets with about 36 facets below the girdle.

rati

An Indian unit of weight that is used for gemstones. A rati is equal to 0.91 carats. The rati has varied in the past and in different regions.

reconstructed stone

Stone that is made from pieces of smaller stones or crystals. Reconstructed stones often have telltale air bubbles. For example, "Geneva rubies" (reconstructed rubies) are made from tiny ruby crystals that have been fused together. This type of stone is generally no longer manufactured (except reconstructed amber, which is stilll made) because synthetic stones are vastly superior to reconstructed stones.

refraction

When light enters a medium with a different optical density (like a gemstone), the light is bent at an angle and also changes its speed.

refractive index

Measure of how light is sent back to the eye from the stone. A higher refractive index indicates a brighter stone. Some stones are doubly refractive, which means that they split light into two different paths. Calcite is an example of double refraction; in very clear rhombs, it will double letters on paper if read through.

regard ring

A ring set with colored stones, the first letters of which spell the word “regard”, ruby, emerald, garnet, amethyst, ruby, diamond. Popular in the second half of the 19th century signifying friendship.

repoussé

A raised high relief design on the front of a metal object made by hammering, embossing or punching the reverse side of the metal to form the design from the back side out.

rhinestone

A simulated diamond made from rock crystal, glass or acrylic. Originally, rhinestones were rock crystals gathered from the river Rhine. Their availability greatly increased around 1775 when the Alsatian jeweler George Frederic Strass had the idea to coat the lower side of glass with metal powder imitating diamonds.

rhodium

Rhodium is a white precious metal. Rhodium is extremely expensive and is often used to plate precious and base metals, giving jewelry a hard, platinum-like sheen.

ring

A band worn as type of ornamental jewelry, most commonly around a finger. Other types of metal bands worn as ornaments are also called 'rings,' such as arm rings and neck rings. Rings can be made of metal, plastic, wood, bone, glass, and other materials. They may be set with a "stone" of some sort, which is often a precious or semi-precious gemstone, but can also be of almost any material.

ring size

Rings are sized using a graduated cone (a mandrel) with markings denoting the ring sizes. The ring is put on the cone and its size is read where it fits snugly on the cone. To size a finger, a finger-ring gauge is used. Sizes in the US and Europe are numerical; sizes in the UK are alphabetical.

rivièrie

Choker type necklace that is a continuous line of gemstones usually of graduated or equal size stones.

roccaille

Jewelry whose design is based on sea life, sea shells, or rocks.

rock crystal

The purest form of quartz and a semi-precious stone.

rolled gold

Early 19th century type of gold plating where a very thin sheet of gold that is laminated to a lesser metal (usually brass). The two layers of metal are heated under pressure to fuse them together. The sheet is them rolled into a very thin sheet and then used to make jewelry or other objects. Jewelry made from rolled gold wear well over time. Rolled gold pieces are marked rolled gold plate, R.G.P., or plaqué d'or laminé.

rondelle

A pierced piece of metal or gemstone strung between the beads in a necklace.

rope necklace

Also called a sautoir, it is any necklace longer than opera length.

rose cut

Also called the rosette cut for diamonds was invented in the 17th century and its use continued until the 18th century. The rose cut has a flat base and triangular facets (usually 24). This cut wastes little wastage stone, but is not nearly as reflective as the brilliant cut, which was invented later.

rough

Minerals or rocks in their natural state that have not been cut.

roulz

A metal alloy that consists of about copper, nickel, and silver. Ruolz is named for the French chemist and musician Vicomte Henri de Roulz, who invented the alloy in the 1800s.

round brilliant cut

A round shaped gem cut having 58 facets, 33 on the crown and 25 on the pavilion.

ruthenium

Abbreviated Ruth or Ru, is a precious metal that belongs to the platinum group of metals. In jewelry, ruthenium is added to platinum alloys; about 5 to 10 percent ruthenium can be added to platinum to harden and strengthen the alloy. It is atomic number is 44.  ^top

- - S - -

safety catch

A secondary closure, usually on a fine bracelet or necklace, used in case the primary clasp opens, preventing the loss of the jewelry. It is often a hinged, snapping loop that is permanently attached to one side of the clasp (often a box clasp), and, when the bracelet is closed, snaps onto the other side of the clasp.

safety chain

A secondary closure, usually on a fine bracelet or watch, used in case the primary clasp opens, preventing the loss of the bracelet. It is usually a chain that is permanently attached to one side of the bracelet, and attaches to the other side with a spring ring clasp (or other type of clasp).

safety clasp

Describes various designs of a secure type of closure on a piece of jewelry. On pins and brooches, a safety clasp often refers to a long pin on a hinge that can be held or released with a secure clasp - often a rotating circle within a circle.

satin finish

A finish on a metal between a matte finish and a brilliant one. This semi-glossy finish is done by making shallow parallel lines on the surface of the metal, reducing its reflectivity.

sautoir

Also known as a rope, it is a necklace longer than opera-length often with an ornament (a tassel or pendant) at the end. Sautoirs were common during the Edwardian era.

scarab

A scarab is a type of beetle. The ancient Egyptians used stones carved in the shape of scarabs extensively in their jewelry and other decorations.

scatter pins

Small pins that are worn together in small groups.

schiller

Is an iridescent or bronze-like luster occurring in some minerals, referred to as labradorescence when it occurs in feldspars. This optical effect is caused by submicroscopic thin layers or flakes of inclusions (lamella) contained within the mineral. These layers can produce a bronze-like luster, golden iridescence, red color-play (as in sunstone), and/or a blue-green sheen (as in labradorite) that flashes when viewed from certain angles. Layers of shiller can also block reflected light, decreasing the stone's brightness. (From the German term for play of colors or glitter)

seal

Engraved (intaglio) of stone or metal used to create an impression on a substance such as wax or clay. Once extensively used as a means of identification; they were only owned and used by relatively important people. Seals were usually mounted in rings or hung on a chain.

setting

A method of securing a stone or other ornament in a piece of jewelry. There are many different types of settings, including the collet, claw, Tiffany, cut-down, pavé-set stones, millegrain, gipsy, and many other types. Some settings are termed closed when there is metal behind the stone, while others are open when there is no metal behind the stone, letting light shine through the stone.

sévigné

A bodice ornament set with gemstones in a bowknot shape.

shank

The part of a ring that encircles the finger.

sheen

The reflected light which come from within a stone. see luster.

signet ring

A ring with a design cut into it which can be impressed into hot wax. In older times, it was used to seal and verify that correspondence was from who one thought it was from.

silk

A whitish cloud of fine inclusions in a stone which cause a star or eye ray effect to be reflected off a gem's surface.

silver

A white metal commonly used for jewelry. The designation "fine" indicates that the metal has been purified as much as possible. It is sometimes called .99 fine. Atomic symbol is Ag  and pure silver has a hardness of 2.5. Other metals are alloyed with silver (usually copper) for silver used in jewelry making. Silver tarnishes after exposure to air. Silver often occurs near copper lodes.

silver 800

Is silver with a fineness of 800 meaning it contains 800 parts per thousand (or 80 percent) silver and 200 parts per thousand (or 20 percent) copper. Silver 800 is used for casting.

simulant, simulated

A material used to imitate a particular gemstone. Different colors of glass have been used for many years to imitate various gemstones. Famous diamond simulants include YAG (Yttrium Aluminum Garnet), CZ (Cubic Zirconia), and recently Moissanite.

slab

A slice of rock or mineral from which cabochons are traced out and cut.

slab saw

A diamond saw designed to cut slabs from rough material.

sleeper

A small hoop-earring made of gold that is used to keep the hole in a pierced ear open.

slide

A jeweled fastener, which slides onto a chain or fabric ribbon.

solder

1. Metal alloy used to join other pieces of metal. Solders melt at a lower temperature than the metals to be joined.

2. The process of joining metal parts or pieces together by melting solder at the joining point.

solitaire

A ring set with a single stone, often a diamond.

specific gravity

Is a comparison of an objects weight with the weight of an equal volume of water. Specific gravity measures the density of a material.

spectroscope

Instrument that is used to identify gemstones. It works by determining the light waves that a stone absorbs; different stones absorb different wavelengths of light.

split ring

A tightly-coiled ring used as an jewelry finding; it can attach charms to a charm bracelet or a clasp to a necklace or bracelet.

spring ring

Also known as a bolt ring, it is a hollow circular metal fastening ring with a spring opening. A tiny spring keeps the arm of this clasp closed. It is used to attach two other rings or links of a necklace or bracelet. The spring ring was invented early in the 1900's. Jewelry made prior to 1900 or so will not have a spring ring clasp.

sprue

Metal bar attached to casting left from the channel used to allow metal into the mold. (see lost wax).

square cut / squarillion cut

A square-cut stone. This fancy cut is relatively new and is also known as a Princess or Quadrillion cut.

SS

Abbreviation for sterling silver.

star setting

Where a gem is set within an engraved star; the gem is secured by a small grain of metal soldered to the base of each ray of the star. This type of setting was popular in the 1890s.

step cut

Benerally used for colored stones. This cut is rectangular to square and has many facets parallel to the edges of the stone.

sterling silver

An alloy of silver containing 92.5% pure silver and 7.5% other metals (fineness of 925), usually copper to give strength while preserving the ductility of the silver and a high precious metal content. Other metals can replace the copper, usually with the intent to improve various properties of the basic sterling alloy such as reducing casting porosity, eliminating firescale, and increasing resistance to tarnish. These replacement metals include germanium, zinc, platinum as well as a variety of other additives including silicon and boron.

stomacher

A very large bodice ornament, usually triangular, filling the area between the neckline and the waistline, also known as a corsage ornament.

strap  necklace

A mesh chain with pendants suspended by short, fine chain resembling a fringe; an Archaeological Revival style during the Victorian period.

strapwork

Decorative pattern in the form of interlaced and crossed straight bands resembling straps.

strass

A high content leaded glass which is faceted to imitate diamonds or backed with colored foils to imitate other gemstones. Developed by Frederic Strauss in the 18th century.

swag

A motif used on a piece of jewelry of festoons of foliage, fruit and flowers.

symmetry

Uniformity of a stone's shape and faceting from one side to another.

synthetic stone

A manmade gemstone which is chemically identical to a natural stone. Typically synthetics have fewer or no flaws unlike natural gemstones. Synthetics tend to be less expensive than naturals. ^top

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table

The large, flat area at the top of a cut gemstone.

temper

To strengthen or harden metal (or glass) by heating it or by heating then cooling it. Harder tempers are stronger, more spring-like, and more brittle (when they are bent, they may break). Softer tempers are weaker but bend easily.

terminal

The decorated ends of a necklace or bangle usually with stylized heads of a ram, lion, dragon, etc.

thermoluminescent

Minerals that emit bright light when heated. For example, chlorophane is a variety of fluorite that emits bright green light when heated.

tiara

A head ornament worn in the crown position.

tie bar

A piece of men's jewelry used to secure a necktie. A tie bar usually has a decorative, bar-shaped front, and a clip on the back that grasps the two parts of the tie.

tie tack

A piece of men's jewelry used to secure a necktie. Ithas a decorative front, and a pin on the back that goes through both layers of the tie. Attached to the reverse of the pin is a chain with a bar that is meant to go through a buttonhole to secure the tie loosely to the shirt.

tiffany setting

a ring with a high, six-pronged solitaire diamond on a simple circular band. This design was introduced by Tiffany & Co. in 1886.

titanium

A strong, light metal (Ti) more and more frequently used in jewelry. It is grayish in color and occurs as a native element.

toggle clasp

Also called a bar and ring clasp, it is a jewelry fastener in which a bar can be inserted into a ring to fasten a piece of jewelry. It is used to attach the two ends of a necklace or bracelet.

torsade

Necklace made of many strands that are twisted together.

trapeze cut

A gemstone cut into an equilateral triangle with a flat top.

tremblant, tremblar

Jewelry with a trembling effect when the wearer moved produced by elements set upon stiff wires that move (en tremblant).

tubogas

A flexible tubular chain, sometimes referred to as gas pipe.

torque (torc)

A open ended neck ring popular in ancient times, particularly among Celtic peoples.

translucent

A gemstone characteristic where some light is able to pass through the stone, but it is not clear enough to see through.

transparent

A gemstone characteristic where light passes freely through the stone, and objects can be clearly seen through the material.

treated

The term given to a broad range of processes that a gem may be subjected to in order to improve its apperance. While most treatment processes are permanant, some may be temporary.

trillion cut

A triangular cut based upon a brilliant style cut and not a stepped facet. The corners of the triangle are truncated (cut short) and there are a variety of facets, giving this cut a sparkling brilliance.

trim saw

A small diamond wet saw used to rough out the shape of cabochons prior to grinding them into final shape.

triplet

A manufactured stone that is made by sandwiching three thin layers of stones together. For example, an opal triplet has a top, protective layer of clear quartz, a thin middle layer of opal, and a base layer of dark, color-enhancing matrix, usually black onyx or ironstone.

troy weight

Measured for precious metals like gold and silver. It has units of pennyweights, ounces, and pounds. Troy ounces and pounds are different from everyday US measures.

tumbler

A motor powered rotating cylinder that smoothes and rounds the surfaces of stones, increasing their luster. As the stones tumble around the cylinder, often in a slurry congaing an abrasive of a specific grit, become smoother and more polished.

tutti-fruitti

Jewelry set with multi colored gems carved in shapes of leaves, flowers and berries and often in a basket design.

twinning

Tendency of some crystals to intergrow in a distinct way or form specific, repeated patterns. See penetration twinning, repeated twinning, and contact twinning. ^top

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ultraviolet light (UV)

Light energy that is not visible to the human eye, and which has very short wavelengths. Many minerals display fluorescence under this type of light.

vermeil

Gold covering a less precious metal, usually sterling silver.

Victorian era

The time when Queen Victoria ruled Great Britain (1837-1901). Many different styles of jewelry developed during this era.

vitreous

Description meaning glass like.

volcanic glass

Another name for obsidian.

vulcanite

A hard, moldable, polished dark colored, anging from brown to black, early rubber. Vulcanite was produced by adding sulfur to vulcanized rubber. It was used for combs, ornaments, and buttons. Also called ebonite, it not the same as gutta percha.

weld

The process of joining two pieces of metal using very high heat. Rolled gold is formed in this fashion.

whiplash curve

Flowing lines that bend and twist as in Art Nouveau designs.

white gold

Gold that has been alloyed with metals such as Nickel or Zinc to bleach out the gold color.

 

wish bracelet

A piece of jewelry with beads. Popular folklore holds that the wearer should make a wish while putting the bracelet on, and rub the beads every day. When the bracelet finally comes off, the wish is believed to have come true.

windowed

Condition where a gemstone is cut below the critical angle (shallow cut, or spread cut), allowing the light to pass through the stone instead of bouncing back and making the gem brilliant.  ^top

- - X-Y-Z - -

YAG

An abbreviation for a diamond simulant. This stands for Yttrium Aluminum Garnet, a synthetic substance.

yellow gold

Gold that has been alloyed with a mix of 50% copper and 50% silver.

YGF

Abbreviation for yellow gold filled.

zamak

Zinc alloy containing some aluminum (3.9-4.5%) and copper (0.02-0.05%).

zinc

A metal which is less commonly used in jewelry applications except as a component of alloys. Atomic symbol Zn.

zoning

A striped color banding pattern, often seen in corundum stones. ^top