Jewelry and Gemstone Glossary of Terms

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Inclusion

In gemstones, an inclusion is any solid, liquid, or gaseous foreign body enclosed in the mineral or rock. The price of amber can vary greatly based on the type of inclusions and clarity of the stone. Amber that contains complete bodies of prehistoric bugs or a well defined fern or leaf can bring a high price, while small bubbles of gas/liquid add only interest to the stone but do not increase the value significantly.

Quartz is another clear stone that when embedded with well defined needle like rutile inclusions can demand a high value.

Inlay

Inlay is a decorative technique using stone, mother of pearl or even glass. It is embedded into another material such as metal or wood resulting in a level surface of the two materials. Inlay is used in jewelry with stones and in furniture with stone or different woods to create a design.

The Zuni Indians used this technique in their jewelry by making a mosaic of different colored stones and bezel setting them in rings, bracelets and pendants.

Intaglio

An Intaglio is a carving where a design is cut or carved into stone or metal so that the carving is below the surface of the material. A cameo is the opposite where the design is carved in relief from the background. This technique was commonly used for seals which were dipped in wax and used to seal a letter or document.

Some of the most common intaglios were carved in the gemstone carnelian and used for signet rings. The earliest known signet rings date back to ancient Egypt.

Iridescent

A gem displaying rainbow-like colors is called iridescent. Iridescence is caused by the reflection of light from the jewel. Mother of pearl is one example of iridescence used in jewelry.

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