Jewelry and Gemstone Glossary of Terms

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Adamantine

The term used to describe a gemstone with a brilliant luster like that of a diamond.

Agate

A form of chalcedony which forms from layers of quartz usually showing varicolored bands. It usually occurs as rounded nodules or veins. The composition of agate varies greatly, but silica is always predominant, usually with alumina and oxide of iron.

Agates are found in the USA, Brazil, Mexico, Africa, Egypt, India, Italy, Nepal, Germany and Asia.

Alexandrite

Alexandrite is a variety of chrysoberyl. Named after Czar Alexander II, it is a color change stone that is green in daylight and light red in artificial light. Mined in Sri Lanka, Rhodesia, Brazil, Burma, Tasmania and the U.S.

Alloy

An alloy is the homogeneous mixture or solid solution of two or more metallic elements or metallic and nonmetallic elements. The alloy is usually achieved by bringing the metals to a molten state under high temperatures and fusing or dissolving them into one solid solution. In jewelry, combining different metals is commonly done to augment the color, hardness and/or luster of the resulting alloy.

Some common alloys used in jewelry manufacture:

Common gold alloys are made by mixing gold, silver, copper, and/or other metals to produce 14K, 18K and 22K gold, white gold (gold and nickel or palladium), rose gold (gold and copper), green gold (gold with silver or silver and cadmium) , and blue gold (a recent gold color perfected by only a few jewelers).

Sterling silver is a combination of 92.5% silver and 7.5% copper, while coin silver is 80% silver and 20% copper.

Brass is an alloy typically of 60% copper and 40% zinc.

Bronze is an alloy of at least 60% copper and tin or other metals.

Pewter is an alloy of low melting point metals including tin, lead, antimony, bismuth and sometimes a bit of silver or copper. U.S. manufacturer's are required by law to make lead free pewter.

Niello is a black alloy of silver, copper, lead and sulfur. It is used to fill engraving, imparting an inlaid effect after the metal is fired and polished.

Nickel silver (also called German silver) is a white metal alloy of 70% copper, 20% zinc and 10% nickel. It contains no silver. Many people are allergic to nickel and because of this, the use of nickel silver in jewelry has been outlawed in some countries.

Almandine

A violet-tinged variety of garnet that ranges from a deep rich red to purplish red to orange reddish-brown color. The most valuable stones contain less orange and brown. There are many varieties of garnet, but almandine is the most common. The star garnet which exhibits asterism is an almandine.

Amazonite

Amazonite is a gem variety of microcline feldspar. It displays a schiller of light which is caused by . Amazonite varies from bright verdigris green to a bluish green and is mined in the United States, Brazil, Zimbabwe, Russia, Australia and Namibia.

Amber

Amber is a fossilized resin from pine trees. Amber deposits have been found that are over 150 million years old, but most amber used in jewelry or ornamentals is between 20-90 million years old. As the sticky resin oozed from ancient pine trees, small insects, plant material, feathers and other small objects in the path of the flow became entrapped. Over time, the resin was encased in dirt and debris and through a process of heat and pressure it fossilized to become amber. Amber exhibits a resinous luster. Also, see reconstituted amber and inclusions.

Amethyst

Amethyst is the purple variety of quartz. To be called amethyst, it must be the purple form of quartz although it can display a wide range of purple shades including purple, lilac and mauve. The most valuable amethyst is a deep purple.

Amethyst is found in geodes and alluvial deposits all over the world and occurs in both crystalline or massive forms. It is a 7 on the Mohs scale of hardness.

"Green amethyst" is a misnomer since the term "amethyst" applies only to the purple variety of quartz. However, that doesn't stop the marketing of these less valuable pale amethyst stones after irradiation and/or heat treatments turn the color green. Properly, after treatment, this stone should be marketed as Prasiolite or Green Quartz, not green amethyst, and it should not be marketed as "rare" since there is an abundance of pale lavender quartz which can be treated to produce a light spring green stone.

Ametrine

This is a bicolor variety of quartz containing both amethyst and citrine colors. The stone is usually cut in facets in a rectangular shape to show both the yellow and purple colors. The Anahi Mine in Bolivia is the only confirmed source for natural ametrine.

Ammolite

Ammolite is the mineralized, fossilized and opalized remains of an ammonite shell which was exposed to tectonic pressure, mineralization, and intense heat.

Ammonite

Sea faring creatures from the Cretaceous period, ammonites were mollusks that built a chambered shell in which they would pump air into the empty chambers which allowed them to float at different levels of the ocean.

Amulet

A small object usually worn around the neck or as a ring to ward off evil, harm, or illness. May also be worn to bring good fortune and protection from harm. A charm, fetish or good-luck piece.

Some common amulets:

The scarab amulet was sacred to the Egyptians and symbolized rebirth. The Ankh is an Egyptian amulet which symbolized eternal life. It is thought to be the oldest and most sacred Egyptian amulet. The Eye of Horus amulet was believed to protect the wearer from evil in life and in the Afterlife.  Also see talisman.

Amulet Bag

A small fringed bag made to hold amulets, talismans or charms.

Ankh

An ancient Egyptian hieroglyphic representing life, or the power to give life. A symbol that looks like a cross with a loop at the top, many Egyptian artifacts depict the gods holding an Ankh.

Anneal

Metal is annealed by heating to make it workable. In the making of jewelry, precious metals become work hardened or stressed when they are hammered, forged, rolled or bent (as in fold forming) making it brittle. Jewelers sometime purchase metals in their annealed state which may be referred to as soft or half hard. Different metals become annealed at different temperatures and jewelers look for the "color" to determine when the metal has reached its annealed state. These colors are described as bright orange, dull red and cherry red.

Anniversary Gifts

The chart below lists the most accepted jewelry and gemstone gifts as endorsed by the Jewelers of America, the Gemological Institute of America (GIA), the American Gem Society,and the American Gem Trade Association.

For a more complete table of anniversary gifts that includes Traditional Anniversary Gifts (Emily Post's original list), Modern Anniversary Gifts, and a list of Anniversary Flowers see our complete anniversary gifts list.
 

Antique Finish

A chemical finish applied to jewelry to make it appear old. Liver of Sulfur has been the industry standard used to apply a darkened gray/black or "oxidized" appearance to silver, copper or bronze and is accomplished by repeated applications. Yellowish, reddish brown, purple or blueish hues can be obtained by using weak solutions sometimes in combination with other chemicals. There are also a number of commercial products available to obtain an antique look.

Antique styles

Various styles of antique jewelry were popular during the Art Deco, Art Nouveau, Edwardian, Georgian, Victorian periods.

Aquamarine

The aquamarine is a member of the beryl family and ranges in color from a pale almost colorless blue to blue-green to pure blue. Some of these stones are heated to enhance their color and change a light colored stone to pure blue. Usually faceted,aquamarines are also cut as cabochons and may then exhibit asterism. Legend tells of sailors who wore aquamarines to keep them safe and to prevent seasickness. The most valuable aquamarines come from Brazil.

Art Deco

Art Deco was a popular design movement from 1920 until 1935. This style is geometric and includes stylised images of airplanes, cars, ships and skyscrapers. It also used natural motifs of organic shapes such as shells, trees and flowers with bold colors and striking blacks.

Art Nouveau

Art Nouveau is a style of art, architecture and design that was popular from 1880 to 1914. It is characterised by highly-stylised and flowing designs which often included floral and other organic motifs.

Asterism

A luminous star like effect exhibited in some gemstones like star sapphires, garnets and rubies. Asterism is caused by inclusions of tiny, parallel, rutile needles and may result in four, six or even twelve rayed stars. (Pronounced: as-ter-iz-mm)

Aventurescence

The effect caused by small inclusions of minerals like mica, hematite, pyrite, or goethite which cause a gemstone to exhibit a glistening or sparkling effect when rotated or moved. The name is derived from aventurine, a green variety of quartz. (Pronounced: ah-ven-shur-ess-ense)

Aventurine

Aventurine is a translucent to opaque variety of microcrystalline quartz. Small inclusions of shiny minerals give the stone a sparkling effect known as aventurescence. Aventurine ranges in color from green, peach, brown, blue and a creamy green. Mohs hardness is 6.5. (Pronounced: ah-ven-shur-ine)

Azurite

Azurite is a copper-based mineral that ranges in color from very deep blue to pale blue. A relatively soft mineral, azurite has a hardness of 3.5 to 4. Azurite is found in many areas of the world including: Australia, the southwestern USA, France, Mexico, Morocco, Namibia, Zaire, and Europe.

Malachite, which is another copper-based mineral, is often found with azurite. When found together it is called Azurite-Malachite.

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