GEM AND JEWELRY GLOSSARY

(March 2024)

The class of property that is most frequently scheduled under a homeowners or other property policy is jewelry. The reason for this is simple. Jewelry, because of its nature (small size, high value) is extremely vulnerable to theft, loss, or destruction. Added protection for such property comes at an added cost. Many insurance professionals, who are entrusted with making sure their customers’ property is protected, have only a nodding familiarity with jewelry. If you doubt this statement, ask yourself if you know the difference between karat and carat.

In order to have a better understanding of this property class, we offer an abbreviated glossary of terms that are common to the world of jewelry. You’ll find that the class contains so much more than diamonds, sapphires, emeralds, rubies, and pearls. This information could help you educate your clients about their possessions that may need additional coverage.

Related Articles:

ISO PM 00 11–Jewelry and Furs Form

Caring for Jewelry and Furs

- A -

abalone pearls–Pearls found or commercially grown in an abalone (single shelled mollusk).

abraided culet–The lowest part of a facet that is scratched, chipped or otherwise marred.

acorn beads–Type of antique Venetian glass bead with distinctive vertical ridges.

acrylic–A transparent form of shatterproof plastic that is used as a glass substitute.

adularescence–See moonstone.

African emerald–Actually a green variety of fluorspar that is mined in South Africa.

African jade–A green-colored, dense variety of garnet.

African trade beads–Derive their name from a past use in parts of Africa as currency. Also known as money beads.

agate–The name agate comes from the Sicilian river formerly called Achates. The Drillo River (modern name of the Achates) is still a major source of this form of chalcedony. Early civilizations, including the ancient Egyptians, used agate for seals and protective talismans. Earlier civilizations created eye beads by carving a hole through an agate disc to symbolize the lens of an eye.

aigrette–Jewelry used to adorn hats or hair and is designed in the shape of a feather plume.

Akoya–Refers to a pearl harvested from the Akoya oyster.

alexandrite–Discovered in the Ural Mountains in 1830 on the birthday of Czar Alexander, which explains its name. It is valuable for it containing crystals that, under various lighting, changes color.

allochroite–A garnet that is dark-colored due to its iron-lime composition.

amazonite–A type of feldspar that is opaque.

alpaca–An alloy that is used as a substitute for silver. It is made primarily of copper that is mixed with nickel, tin, and zinc.

alpacca–See alpaca.

alloy–Any combination of metals that result in increasing metal strength and reducing vulnerability to corrosion.

altered stone–Any stone that has been changed in appearance, particularly in color, by an artificial process. Heating, irradiation, and dyeing are some of the processes used to change gemstone appearance.

amber–Not a stone, but rather tree sap that has become fossilized. It is cut, polished, and treated as a valuable gemstone, especially when a piece contains a preserved insect. There are two varieties: Butterscotch (found in Eastern Europe) and Brown (found primarily in Siberia).

American cut–Refers to style of handmade glass created in the U.S. between 1876 to 1917 that is highly collectible.

amethyst–Its name comes from Greek meaning “not drunk,” which stems from a belief that the purple (wine colored) stone could relieve hangovers. This stone is commonly used in necklaces, pendants, rings, and bracelets.

ametrine–A bi-colored variety of crystalline quartz containing the characteristic colors of both Citrine and Amethyst.

amorphous–Amorphous means without form and refers to gems such as amber, ivory, or jet which don’t have a formal internal structures. Opposite of crystalline gems.

amulet–Any object worn with the belief that it bestows good fortune or wards off misfortune.

angle of incidence–The angle at which a ray of light enters a stone as measured from normal.

angle of reflection–The angle at which a reflected ray of light leaves a surface as measured from normal.

angle of refraction–The angle at which a reflected ray of light leaves a surface as measured from normal.

annealing–A heating, then slow-cooling process used in handling metal and glass, which increases durability.

anisotropic–Term used in gemology for double refraction.

ankh–A symbol that represents eternity or eternal life, created in Egypt.

anodization–Coating used on metals to make them less vulnerable to corrosion and increase the ability to apply glues or paints.

anthill garnet–Garnets found near Arizona anthills due to ants removing them as they build underground nests.

aqua regia–A powerful acid solution that is used to test for gold and platinum content.

aquamarine–Appears in a range from light to dark blue or blue-green stone and, in its highest quality, is transparent. It literally means “sea water” and it is a harder stone.

arabesque– Following (moving in the same form as piece it decorates) scrollwork. It typically appears as curlicues in low relief.

Arctic opal–A blue-green gemstone that consists of azurite and malachite which is found in Alaska.

arsenic–This poison forms a very tight, chemical bond when it is used to color glass (or to remove unwanted color from glass) which makes it completely safe to wear.

Art Deco–A style which features non-natural elements such as sharp angled, geometric shapes, bold colors, molded or faceted beads, as well as the use of chrome and plastics.

Art Nouveau–Also known as "Victorian" or "Edwardian." This style features fluid lines, natural colors, and natural, particularly floral themes.

artform jewelry–Jewelry created by use of molds.

artificial pearls–An obsolete term replaced by the term “cultured,” since artificial implied fake or synthetic. See pearls.

artificial stone–A man-made, synthetic, or imitation gem.

asterism–A star-like light effect that is usually only seen in carbochons.

aventurine–A quartzite gemstone, usually comes in green (contains mica) or blue (containing cobalt).

Aurora Borealis–Refers to iridescent, faceted glass beads.

Australian jade–See chrysoprase.

awabi pearl–Japanese name for abalone pearls.

axe stone–See jade.

azurite–Similar to malachite, except that it typically appears in a deep and vivid shade of blue.

- B -

bail–A metal support from which a pendant hangs from a cord or chain.

ballerina setting–A setting that raises the gemstone above the ring’s shank, like a lifted ballerina.

band–A simple ring with uniform width and depth. When it contains jewels, they are usually of the same size.

bar ring–A style of ring band consisting of multiple bars that are connected by woven metal.

baroque–Beads or rounded stones or pieces of glass that are irregularly shaped.

barrel clasp–A connector that is barrel-shaped and consist of two parts that are screwed together to keep a bracelet or necklace in place.

base metal–Any common (as opposed to precious) metal such as copper or nickel.

bauble–Slang for any piece of large, flashy and low-value ornamental jewelry.

bauxite–A reddish-brown gemstone which is actually an ore of aluminum. It is found in tropical climates such as Nigeria. Because of it coloring, some African cultures revere it as a symbol of life’s force.

bayadere–A pearl necklace consisting of multiples of twisted strands.

bead setting–A method of securing a faceted stone, it is normally used to secure very small gemstones, usually in multiples.

bearing–The supporting ledge of a stone setting.

bell cap–A finding to which solid beads or stones are glued to make pendants.

beryl–An important mineral species that includes aquamarine and emerald.

betrothal ring–A plain band made of precious medal that, originally, represented an intent to marry (used prior to marriage).

bezel–1. A thin strip of metal which secures a gemstone to a piece of jewelry. 2. The sloping facets on a brilliant cut gemstone.

bicone–A bead with ends which taper off into cones.

birthstone–A gemstone that designates a wearer's month of birth.

bixbite–A strawberry-colored beryl.

blocking–The process of placing the facets on a stone.

bloodstone–A variety of quartz called chalcedony. It exists in different shades of green with red and brown spots caused by iron minerals. The spots look like drops of blood.

body color–The dominant hue within a gemstone.

Bohemian crystal–Glass that has been hardened by adding lead.

Bohemian glass–Glass made in Bohemia, formerly a country in Eastern Europe which is now part of the Czech Republic.

book chain–A chain consisting of rectangular links that resemble books. From the Victorian era.

bort–A term for industrial grade diamonds.

boule–A manufactured (synthetic) gem created by a molten mixture that cools and hardens after being poured into a tear-shaped mold.

box setting–A method of stone setting in which the gem is enclosed in a box and the edges of the metal are pressed down to secure the stone.

Brazilian aquamarine–An alternate name for blue topaz.

Brazilian rock quartz–A gemstone quality variety of quartz found in Brazil.

brilliancy–The total amount of white light returned to the viewer by a gem. This includes internal and external reflections.

brilliant–Refers to a method of cutting gemstones with facets designed to enhance their light reflecting capacity.

briolette–An oval or pear-shaped diamond with a surface of triangular facets.

broach–A jewelry pin.

bruting–A method of rough-diamond fashioning by rubbing one diamond against another.

button earring–Any earring without movable parts.

- C -

cabochon–A highly polished gemstone with a dome top and no faceting.

cabochon cut–A smooth, rounded cut which does not contain any planes (facets).

cage ring–A ring with a center gemstone that is tightly surrounded by bars of similar or other gems.

calibre cut–Gemstones cut to a specific, standard size to prepare them for mounting.

caliper–A pincer-like tool used to make accurate gemstone measurements.

cameo–A raised design or figure that is cut out of a gemstone.

cane –A long rod of glass or clay (with or without a pattern) that is used to make beads.

carat–A unit of measurement for weighing gemstones; one carat is equal to .2 grams (note that this term is different from karat, see below).

carnelian–A red or brown gemstone that is a variety of chalcedony.

casting–Refers to the technique of reproducing an object in metal from a wax model.

cathedral ring–See cathedral setting.

cathedral setting–A metal band with an arch design that is similar to cathedral arches.

chalcedony–Any type of quartz which has a cloudy, non-crystalline appearance, such as agate. Its common colors are blue-gray, cream, and reddish brown.

chandelier jewelry–Any jewelry piece with multiple dangling elements suspended by a single support.

change of color–A phenomenon seen in some gems which have a different color in natural light than in artificial light. This color-change is caused by selective absorption and transmission of light.

channel set–A setting composed of either rectangular or square-shaped gems positioned side by side.

chatoyancy–The appearance of well-defined bands or threads of light across the surface of a gemstone.

checking -The tendency of opals to crack when exposed to heat or drying air.

chevee–A gemstone with a smooth concave depression.

chevron–A difficult bead pattern that features layering white, red, and blue glass.

chip–A popular, common name for a small rose-cut or single-cut gemstone.

chocolate diamonds–Diamonds with impurities that create a brown hue.

choker–A short, collar length necklace.

chrysoprase–Refers to a type of chalcedony consisting of a bright green shade that is created by its nickel content. It has an oily surface, similar to vaseline glass. It is popularly used for beads, cameos, and cabochons. The highest quality chyrsoprase is found in parts of Australian.

cinnabar– A brilliant mineral of red or vermillion that is often used as a red pigment and which is particularly valued in China where it is frequently used for inlays and in jewelry. The mineral comes from mercury ore.

citrine–A type of crystalline quartz which has a color range from pale yellow to a deep orange yellow or brown yellow and also appears from opaque to translucent. This stone is sometimes created by treating amethysts with heat.

Claddagh ring–An Irish ring depicting two clasped hands.

clean–A trade term for gemstones which are free of noticeable flaws.

cleavage–A smooth, flat break or separation in a gem along the direction of its atomic structure.

cloisonné–Describes the process of filling thin wire partitions–cloisonnes in French–with enamel.

cloud/cloudy–A group of small, white inclusions that give a cloudy appearance to a diamond.

cluster setting–Closely set gemstones arranged to give the illusion of a single, larger gemstone.

coated stone–A gemstone covered by an artificially applied transparent material to enhance its color.

cobalt glass–Glass colored with cobalt to create a deep blue color.

coin jewelry–Any jewelry that features coins in its design.

coin pearls–Natural pearls with a flat, coin-like shape.

collet set–A variation on box setting in which the sides of the box are filed away to allow more light to enter the gemstone.

color zoning–Uneven color in gemstones in irregular patches. It can be either different colors or different tones of the same color.

colored stones–A gemstone other than a diamond.

conflict diamond–Any uncut diamond mined within areas experiencing armed disputes which are used as a method to illegally finance continued conflict.

Conflict-free diamond–Any uncut diamond without taint involving its mining, production, or distribution. The literal opposite of conflict diamonds.

convertible necklace–A necklace with hinges that permit them to form more than one design.

coral–Describes the calcified skeletons of marine organisms that live along coastlines of a variety of saltwater bodies such as the Western Mediterranean, Japan, several island groups, and the Red Sea.

corundum–Corundum is an aluminum oxide which is called a ruby when red and sapphire in other colors (including lighter shades of red). The different colors are caused by the presence of chrome, iron, titanium, etc.

cranberry carnelian beads–A rare, antique Venetian glass bead which acquires a true red color by dissolving gold into glass.

critical angle–The greatest angle measured from normal at which light can be refracted out of a stone. Also, a small angle at which light is completely internally reflected.

crown setting–A collet setting consisting of a flared cylinder with one end of the cylinder notched to form prongs.

crystal–See lead crystal.

cubic zirconia (or CZ)–Synthetic (artificially created) Zircon, commonly used to imitate diamonds.

culet–The extreme low (lowest) point or facet of any stone.

cultured pearls–See pearls.

cushion cut–A gem that is cut into a square with the corners rounded into facets.

cut–The specific form into which a stone is fashioned. It is one of the deciding factors in gemstone value.

cuvette–A raised relief carved into a gemstone in a concave depression.

Czech glass–See Bohemian glass.

- D -

damascening–Designs consisting of hard metals inlaid with softer metals.

danburite–A mineral in the silicate family. It has a luster similar to fine china (vitreous) and may be colorless, brown, pink, or yellow.

demantoid–A bright green variety of garnet.

demi parure–Matching jewelry containing two or three pieces. See also parure.

dendritic–An inclusion pattern shaped like a tree or fern.

diadem–A diadem is a tiara, a circular or semi-circular piece of jewelry worn on the head.

dichroic–Any gem that, from different angles, appears to have different colors.

dispersion–The separation of light into its spectral colors as it passes through a gemstone.

Dogon donuts–Disc beads made from old Dutch cobalt glass, by the Dogon, an ethnic group in Mali, Africa.

double marquise jewelry–Jewelry containing two marquise cut gemstones.

double refraction–The separation of a beam of light into two separate beams as it enters a gemstone. The two beams travel at different speeds. It can be used to distinguish one gemstone material from another.

doublet–A combination of a lesser value gemstone half glued to, usually, a half of colored glass, resulting in a gem that fakes the quality of a much more valuable stone.

dramatic jewelry–Any jewelry with a particularly novel or showy design–typically costume jewelry.

dream beads–A pattern of Venetian glass beads which features colors and gold particles that appear to be suspended within.

durability–The combined characteristics of hardness, toughness, and stability in gemstones. This is one of the deciding factors in gemstone value.

Dutch glass–Beads produced by Dutch traders for commerce, but, because of differences in production, the beads were less durable and colorful than Venetian glass.

dyed stone–A gemstone to which an artificial stain is added to improve color or to imitate a more valuable gemstone.

- E -

eight cut–A cut containing four facets on a gem’s upper and lower parts; usually used with small stones.

Elbaite–The proper mineral name for tourmaline. This mineral is named after its place of origin, Elba Island.

elbow bead–A long, elbow-shaped, Venetian glass bead that was last produced in the 1700s.

emerald–Emerald (Greek “green stone”), a hard, but brittle gemstone, is the most valuable form of beryl. Colors range from various shades of green, blue green, or yellow green. Colombia is an important source of this gemstone.

enameling–Where color substances, melted in a kiln, are used to decorate metal, including metal beads.

engraving–Refers to creating a pattern (including writing) on metal.

estate jewelry–Refers to previously owned jewelry (not necessarily antique).

ethical–Processes in the production of gems that avoid harm to persons or environment.

excel–A process that uses a form of reflective polymer that is applied to emeralds to correct various gem deficiencies, resulting in an enhanced appearance.

extender–An extra length of chain that allows a necklace to be adjusted.

eye bead–This pattern, also known as the "evil eye" bead, is the eldest of bead patterns that were worn for good luck. See agate.

- F -

face–The plane surfaces which form the sides of a crystal.

facet–A small, flat, polished surface on a gemstone.

facet cut–Cutting a gemstone with a number of flat planes to enhance light reflection. The opposite of cabochon cut.

fancy cut/fancy shape–Any style of gemstone cutting other than the round brilliant or single cut.

fancy diamond–Any diamond with a body color strong enough to be attractive.

faux–French meaning fake or false. Jewelry consisting of non-precious metals and/or stones.

feather–A trade term referring to any inclusion within a gem, usually a jagged, irregular fracture, which appears white.

feather bead–Glass beads decorated with a feather-like pattern and which originated in Venice, Italy.

fede ring–Any ring design of clasped hands.

feldspar–Certain minerals that habitually form crystalline rocks.

ferrer’s emerald–Glass stone that is used to imitate emerald.

ferronniere–A jewel centered on a narrow, circular bands that is worn around one’s head.

fetish–An amulet, bracelet, or pendant in the shape of a person or an animal.

fibula–A safety-pin style brooch.

Figaro-link chain–A chain design, consisting of alternating elongated and round links.

figural–Refers to any jewelry that is designed to look like real objects such as animals, baskets, flowers, humans, etc.

filigree–A method for producing delicate, detailed patterns in metal, particularly clasps, and bead caps.

findings–Refers to fasteners and construction components that are used in making jewelry.

fingerprint inclusion–Liquid, gas or solid flaws in gemstones which align in the form of a human fingerprint.

fiorato–Italian name for a rose bead. See rose bead.

fire–The play of color on or within a gemstone as a result of dispersion.

fissure–See fracture.

flaw–Any visible imperfection within a gemstone.

floater necklace–A bead necklace that uses wide bead spacing and very thin string or line in order to create the effect that the bead(s) are floating.

flowering obsidian–Volcanic glass that appears in dark brown or black with white, snowflake-like highlights.

fluorescence–The emission of visible light when a gemstone is exposed to ultraviolet light. This is a method of distinguishing one gemstone from another and a natural gemstone from a synthetic gemstone.

foil–Thin metal leaf (typically gold or silver) that is used as a backing for imitation gemstones or faceted glass. Foil enhances brilliance and color.

foil backed–The adding of a layer of metallic foil to the back of a gemstone to improve its color or brilliancy.

four “C”s, the–Refers to the major characteristics in determining the value of a gemstone (usually a diamond): cut, carat (weight), clarity (presence of flaws), and color.

fracture–A break or chip in a gemstone in any direction other than along a cleavage plane.

free-form stones–Gemstones with odd or uneven shapes, usually used as charms.

French ambassador beads–Special, knee-length necklaces given to France’s ambassadors during the reign of Louis XIV.

French ivory–Trademark name for granular surfaces celluloid, porcelain or plastic that is used to imitate ivory tusk.

French screw back–A very small, threaded clamp attached to earrings so they could be worn by persons without pierced ears.

fruit salad–Costume jewelry which features multi-colored, molded stones.

full-lead crystal–A higher quality, brilliant crystal that contains at least 30% lead oxide.

- G -

gagete–See jet.

gahnite–A variety of spinel, bluish in color, having a high zinc content.

gallery–A gallery is a decoratively perforated metal strip that is either open or closed. Open versions are often modified by jewelers to become gemstone settings.

garnet–A gemstone with grain-shaped crystals. It comes in a wide range of colors from black to clear, though the most commonly marketed variety is red.

gemstone–A precious stone (or pearl) that is suitable to be cut or polished for use in jewelry.

gemology–The study of gemstones, specifically identification, grading, appraisal, marketing, and fashioning.

geode–A rock which contains a cavity lined with quartz or other gemstone crystals.

German silver–See nickel silver.

gild–To cover an object with a thin layer of gold.

girandole–An earring consisting of three pearls dangling from a large gemstone.

girasol–A gemstone with a glowing, milky sheen that moves as the stone is moved in the path of a light source.

girdle -The outer edge of a gemstone.

givre beads–From the French word for frost, they are transparent glass beads that are merged around a translucent core.

glazing–A thin layer of melted glass used for decoration and/or protection.

glyptic -The art of engraving or carving gems.

gold filled– Refers to jewelry containing a common metal such as nickel, which is coated with gold.

Golden jubilee diamond–Discovered in 1985, a brown, 545 caret gem. Currently, the world’s largest, cut, faceted diamond.

gold-lip oyster– A kind of oyster used in different countries to create cultured pearls that range from off-white to deep yellow.

goshenite–Colorless, pure beryl.

grelot–Small, pendant-shaped beads.

Grey gold–A form of gold that contains a high level of iron, giving it a greyish hue.

group–Two or more chemically related gemstone materials which are similar in structure and physical properties.

- H -

habit–The natural shape usually formed by a given crystal.

hair jewelry–Glass brooches that are used to preserve hair as a decorative keepsake.

hand-knotted–Refers to beads which are strung separately with a knot tied between each bead. This method of stringing creates a more durable strand and reduces wear and tear on the beads.

hardness–A gemstone material's ability to resist scratching.

harlequin pearls–A necklace consisting of multi-colored, Chinese, freshwater pearls.

hawk’s eye–Blue, green, or grey quartz with horizontal crocidolite inclusions that result in creating a gem that looks like the eye of the predatory bird.

head–An added finding to secure a gemstone in a prong setting.

headpins–Short wires that are used for threading beads onto earrings or pendants.

heat-treatment–Heating a gemstone material to improve its color.

heavy liquid–A liquid of known specific gravity, used to test the specific gravity of a gemstone.

helenite–Manmade stones made from the rock dust created by the Mt. St. Helen’s eruption and which are sold as souvenirs.

heliotrope–See bloodstone.

hyacinth–Refers, generally, to a yellow, orange, brown, golden-brown, or reddish-brown form of (natural) zircon.

- I -

illusion setting - A setting in which the surrounding metal's surface is cut or shaped to appear to be part of the gemstone. This technique is often used to enhance the perceived size of small diamonds.

inclusion–Any foreign mineral or substance "included" within a gemstone. Though generally considered to be flaws, they sometimes enhance the value of certain gems.

India glass–Glass beads from India.

indicolite–A blue-green or green variety of tourmaline.

ingot–Metal that is poured into a mold to form a bar or brick.

intaglio–A decoration that is carved into a gem.

intensity -The color of a gemstone from bright to dull.

invisible necklace –See floater necklace.

iolite–A blue gemstone, named from “ios,” which is Greek for violet. Historically used by Vikings to shield their eyes from the sun during sea voyages.

iridescent glass–Glass mixed with arsenic (which safely bonds to glass) to create a rainbow or pearl-like luster.

irising–Describes a thin, air-filled crack within translucent gems that creates iridescence.

ivorine–See French ivory.

ivory–Material that composes animal teeth, particularly hippopotamus teeth and walrus and elephant tusks.

- J -

Jabot pin–A tie pin, decorated with a gem that were first popular in the1920s.

jacinth–See hyacinth.

jade–A form of nephrite that is treasured in China and is believed to bring good luck as well as having medicinal value.

japanned–Refers to jewelry containing metal that has been finished with black lacquer.

jasper–A variety of chalcedony that is usually striped or spotted. In ancient times it was used in seals and to ward off drought.

jasperized wood–Petrified wood. It is wood that has fossilized (where the original wood has been replaced with minerals, resulting in a stone-like wood replica).

jelly belly–A piece of jewelry that has a center made from glass (or clear lucite).

jet–A carbon mineral (lignite coal) that, when cut into facets, has the stunning appearance of a black diamond.

jet glass–Glass pigmented (colored) with coal.

Job's tears–Refers to the incredibly hard seeds derived from a variety of wild, tropical grass plant. The seeds (white) are transformed into jewelry by a process of drying, coloring, and polishing. Typically, they’re used to make bracelets and necklaces.

jump-ring–Any small wire ring for connecting or suspending a piece of jewelry.

- K -

karat–Refers to an alloy’s gold content. 14 karat describes a content of roughly 60% or greater, while “pure” or 18 karat gold; surprisingly, may have as little as 75% gold content. (Not to be confused with the term, carat, see above.)

keeper ring–A ring that is worn with another, more valuable, ring. It’s placed on the finger after the first ring as a safeguard against loss (slipping off finger).

king cut–A cut used in large stones which contains 86 facets.

king topaz–Refers to a sapphire that appears from yellow to yellow-brown.

kunzite–A type of spodumene that has a lilac-pink color.

- L -

lab gems–General reference to any gem that is manufactured rather than natural.

labradorite–A grey form of feldspar that, when polished has grillian blue, green, or red highlights.

lampworked glass–Any glass that is hand-shaped from glass canes or tubes which are held over flames. The name came from the fact that the glass was originally (1700s) formed in flames from oil lamps.

lapidary–Refers to cutting, shaping, polishing precious and semi-precious stones in order to create jewelry. This term is also used to refer to persons who perform these skilled tasks.

lapis–A very soft, beautiful royal blue stone. It is commonly associated with royalty and often appears with bits of calcite (white) or pyrite (gold).

lariat–A necklace designed to look like a lasso.

lavalier–Refers to pendants, gemstones that dangle from a neck chain.

lead crystal–High-quality glass that contains a minimum amount of lead oxide. The higher the lead oxide content, the higher the quality of crystal.

leaf–See metallic leaf.

lentil cut–Refers to a cabochon (smooth, no facets) cut stone where the upper and bottom portions are identical.

lignite–See jet.

lobster claw clasp–A spring-loaded jewelry fastener that looks like a lobster claw. It is used to attach separate pieces or separate ends of jewelry or accessories together.

locket–A hinged pendant that is designed to hold a photo, charm or particularly important memorabilia or souvenir.

loupe–A type of magnifying glass used by jewelry professionals to examine gemstones, particularly diamonds.

luster–The appearance of a surface resulting from reflected light.

- M -

mabe–The term used in Japan for cultured pearls that appear as half-spheres.

make–A trade term referring to the quality of a gemstone's cut.

malachite–A copper mineral with a pattern of dark green and yellow bands. Historically it was believed to ward off evil or to attract financial success.

Maltese cross–A cross whose four equal-length arms become wider the farther they get from the center.

marcasite– A form of iron pyrite with a shiny appearance, typically has a faceted surface.

mass aqua–A misleading term for what is actually blue glass.

matinee-length–A single strand necklace with a length of between 22 to 23 inches (56 to 58 cm); a length.

matrix–The rock in which gemstone material is found.

maw-sit-sit–A rare gemstone. It is green with dark veins (ranging from deeper green to black) and, sometimes, white spots. It may appear translucent to opaque.

melee–A small (under .20 carat) diamond.

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

metallic leaf–Extremely thin sheets that are made from rolled or pounded copper, gold, platinum, or silver. Leaf is used for applying to base metal surfaces.

Mexican jade–A form of stalagmitic calcite that has been dyed.

millegrain–A style of setting in which the stone is held in place by a row of tiny beads along the girdle of the stone.

mine cut–An old style of cutting gemstones in a thick, cushion shape.

mixed cut–Describes a stone that has its upper and lower portions cut in two different styles.

Moh’s Scale–A categorization of minerals according to their hardness or resistance to scratching. Diamond is the hardest.

mokume-gane–A Japanese metal-work technique that gives precious metals a wood-like appearance.

moldavite–A rare, glassy, translucent, dark green gemstone that is made of a mineral that is similar to silica. It is rock material that was fused during the impact of a meteorite.

molded cameo–Cameos created by molding rather than carving. Usually is made from pouring glass, plastic, or porcelain into a decorative mold.

money beads–See African trade beads.

moonstone–A feldspar gemstone featuring adularescence, which describes a sheen that appears to float within a stone.

mother-of-pearl–A literal reference to the iridescent inner lining of a pearl oyster shell.

moukaite–Found in Australia, it is a variety of Jasper that ranges in color from pink to reddish brown and has gold and white bands.

mounting–The portion of a piece of jewelry which holds a gemstone.

murrina–Italian word for the dust (usually gold) suspended in glass.

mya yay–The Burmese name for high quality (translucent) jadeite.

- N -

nacre–The layers of materials secreted by mollusks that form pearls.

natural gemstone–Valuable stone that is formed by nature, without human influence.

nephrite–A form of jade, appearing in darker shades of green, that was originally found and used in China.

niccolo–A form of onyx that is used as a surface for engraving.

niello–An alloy (black) that is used in engraving and is a combination of copper, lead, silver and sulphur.

night emerald–See peridot.

noble metals–Gold, platinum, and silver.

normal–In the study of light, an imaginary line perpendicular to a surface. This term is used in gemology to describe the angle at which light strikes an object.

- O -

obsidian–Glass that is formed by lava that rapidly cools. The name is derived from its discovery by a Roman named Obsius.

olivine–See peridot.

onyx–A banded variety of quartz that ranges from translucent to opaque and appears in a color range from orange to brown which alternates with straight white bands. This gemstone is commonly dyed to create black onyx.

opal–A gemstone that is a variety of quartz which may appear with a rainbow luster (precious opal) or reddish-orange in color (fire opal).

opalescence–Milky or pearly appearance.

opaque–The quality of not allowing the transmission of light.

optical properties–The behavior of light within a material.

organic gem–Naturally occurring substances wholly or partly derived from plants or animals. Examples are coral, jet, or pearls.

orthoclase feldspar–See moonstone.

- P -

padre beads–See prayer beads.

parure–Matching jewelry containing three or more pieces such as a necklace, choker, brooch, earrings, bracelet, and ring. Also see demi-parure.

paste–Refers to jewelry made with glass that is cut to imitate faceted gemstones.

pave'–Small stones set in the surface of metal as close together as possible.

pavilion–Refers to the bottom side of a gemstone.

pearl–A pearl is created when a mollusk secretes layers of calcium carbonate around an irritant that has entered its shell. When this happens by chance, the pearl is “natural.” Cultured pearls are made when the irritant is intentionally placed in the shell.

pendant–Any item that is suspended from a chain or necklace.

perfumed beads–Treating beads to release a fragrance as they are warmed by the body.

peridot–A transparent stone that appears as green or olive green.

phenomenon–An optical effect which appears in certain gemstone materials that is often revealed by or enhanced by proper fashioning.

phosphorescence–A continuing glow exhibited by some gemstones after the source of illumination has been removed.

pietra dura–See mosaic.

pique–Inlaying of gold or silver into genuine tortoise shell, ivory, or horn.

platinum–A soft, heavy, gray metal that can be highly polished. At times platinum has a higher value than gold.

play of color–Prismatic flashes of color seen within a gemstone.

pleonast–A black variety of spinel.

prasiolite–See vermarine.

prayer beads–Glass beads which are used in rosaries.

prong–A narrow tab of metal folded over the girdle of a gemstone to secure it in a setting.

pyrope–A very dark, purplish variety of garnet.

- Q -

quadrillion cut–A square cut stone.

quartz–A very common mineral made of silicon dioxide which is found in any color. Varieties include agate, amethyst, bloodstone, and a host of other gemstones.

quincite opal–See quinzite opal.

quinzite opal– Pink to reddish-colored opal.

- R -

reconstructed stone–A man-made gemstone produced by fusing together small particles of a natural stone.

recycled–Metals and gemstones that are re-used to produce new jewelry.

reflection–Light returned to the viewer after striking a surface without entering it.

refraction–The change of velocity and resulting bending of light as it passes from one medium into another medium of different optical character.

refractometer–An instrument used to measure the degree of refraction with a gemstone. This is one of the primary tests to identify gemstone material.

retticello–White glass in a delicate, lattice (criss-crossed diagonal) pattern.

rhinestones–Artificial stones made either from crystal quartz, glass or paste that are designed to, typically, imitate diamonds, emeralds, or rubies.

rhodochrosite–A softer stone made of carbone. It appears in a range of colors from red to off-white, typically containing curves of various color shades.

rosarios–Beads with a chevron pattern that are used in cardinals’ rosaries.

rose bead–Rose-shaped bead pattern which originated in Venice.

rondelle–Rounded, doughnut-shaped disk.

rose opal–See quinzite opal.

rose quartz–A deep red quartz that, traditionally, should be reserved as a gift to one’s true love.

rough–Uncut or unfashioned gemstone material.

roundels–Tiny round beads often used as spacers or separators.

rutilated quartz–Quartz which contain yellowish crystals which range from opaque to transparent.

- S -–

sand-cast–Glass beads made from casting powdered or pulverized glass in sand, resulting in a granular finish.

sapphire–See corundum.

satina bead–Bohemian glass beads with a satin-like finish.

sautoire–An Edwardian era, long necklace that was supplemented with a pendant or tassel.

scarab–Refers to any gemstone that is cut in the shape of a beetle.

scrimshaw–Carved or engraved ivory or vegetable ivory. The engraved lines and textured surfaces are often colored with inks and dyes.

serpentine–A pale green translucent gemstone that looks very similar to alabaster and jade. It is commonly used as a jade substitute (often fraudulently).

setting–A mounting or the portion of a mounting which actually holds the stone.

simulated pearl–Consists of a stone nucleus surrounded by layers of plastic nacre.

smoky quartz–See topaz.

snowflake obsidian–See flowering obsidian.

sodalite–A gemstone that is similar to Lapis, but without shiny flecks of gold or silver.

spessartite–An orangish or reddish variety of garnet.

spinel–A mineral which resembles corundum, especially red spinel which has been mistaken for a ruby.

spodumene–A mineral consisting of aluminum silicate and lithium and comes in the shape of prisms.

stability–The ability of a gemstone to resist deterioration.

star stone–A gemstone in which the phenomenon of asterism is visible.

sterling silver–An alloy combination of roughly 90% silver and the remainder of copper and/or zinc that strengthens the silver, making it more suitable for use in jewelry and silverware.

strass–Glass containing a high amount of lead oxide and cut to simulate a gemstone.

substitute–A substance used to imitate a more valuable gemstone. The substitute substance may be natural or man-made.

sustainability–Practices in gem production and distribution preserve human health and environmental well-being.

synthetic–A man-made gemstone that has nearly the same physical, optical, and chemical properties of a natural gemstone.

- T -

table–The horizontal flat surface on the crown of a faceted gemstone.

talisman–See amulet.

tanzanite–A mineral called blue zoisite that ranges from pale blue to reddish-brown. It is named after Tanzania, the country where it is mined.

tiffany setting–A solitaire (single-stone) setting for a faceted stone consisting of six long, slender prongs.

tiger’s eye–A black, quartz stone that, due to staining from iron oxide, contains yellow and golden-brown stripes.

tone–The relative lightness or darkness of a color.

topaz–A salt-like mineral (fluosilicate) of alumina. It occurs naturally in a rhomboid shape and appears in a wide range of colors, including blue, yellow (and related shades), pink, green, red, orange and others (as well as clear/colorless). It is a popular gemstone that is also a birthstone (November).

torchworked glass–See lampworked glass.

tourmaline–A family of closely related silicate crystals that come in a large variety of colors.

translucent–A substance that allows transmitted light to clearly pass through. Objects cannot be seen through a translucent substance.

transparent–A substance that allows transmitted light to clearly pass through. Objects can be seen through a transparent substance.

trilliant–A faceted stone with a triangular shape.

trinket–See bauble.

tulip setting–A prong setting with a small base that is attached to the body of the jewelry piece. It usually has a peg on the base which is inserted into a hole for solder attachment.

tumbled stone–A gem with an irregular or baroque shape.

turquoise–A gemstone which name means Turkish stone.

T.W.–Abbreviation for total weight.

- U -

unakite–A green mineral that contains pink or red spots. It consists of granite, epidote, and feldspar.

uranium glass–See vaseline glass.

utahlite–A gemstone similar to chrysophase and turquoise. It is translucent, in shades of green (with hints of blue or yellow).

uvarovite–A very small, green-colored type of garnet that, because of its small size, is rarely used, so is popular with collectors.

- V -

vabanite -A type of jasper, appearing as a yellow-flecked, brown gem.

varasite–See utahlite.

vaseline glass–Refers to green or yellow glass that looks like vaseline ointment and which, under ultra-violet light, glows. Also known as uranium glass since it was originally made with small amounts of uranium.

vegetable ivory–Any hard, white, or cream-colored product of a plant which simulates elephant ivory. It has gained in popularity as the harvesting of animal has been banned or severely limited.

vermarine–A light to medium green quartz that is created by carefully treating amethyst with heat.

vermeil–Refers to gilding a silver bead.

verneuil process–Refers to the method used to create boules. See boule.

- W -

water sapphire–See iolite.

wax pearls–Hollow glass beads that are filled with was to simulate pearls.

wedding band–See betrothal ring.

wedding cake beads–Glass beads that have been lampworked, consisting of colorful overlays.

white gold–A silver-colored gold caused by the presence of nickel, platinum, or zinc.

white hearts–A core of white, wound glass found in the center of red eye and cranberry carnelian beads.

wiluite–See African jade.

- X -

xaga–A form of obsidian that originates from California.

xalostocite–A grossular formation of pink, garnet that is found within white marble. Named after Xalostoc, Mexico, its place of origin.

xyloid jasper–See jasperized wood.

- Y -

YAG–Short for yttrium aluminum garnet. It is a lower luster, man-made diamond.

YGF–Abbreviation of Yellow Gold-filled.

yellow gold–An alloy that combines copper, gold, and silver.

- Z -

zamak–A zinc alloy containing small amounts of aluminum and copper.

zerfass emerald–Glass dyed green to simulate emerald.

zinc spinel–See gahnite.

zircon–Natural gemstones which, in colorless variety, are very similar in appearance to diamonds, though are much softer and are easily scratched. Also come in brown and green and, if heated, can appear in blue or golden shades.

zirconia–See cubic zirconia.

zoisite–See tanzanite.