gem, ornamental mineral or organic substance

gem, commonly, a mineral or organic substance, cut and polished and used as an ornament. Gems also are used as seals (items of assurance) and as talismans (good-luck charms). For birthstones, see month.

Sections in this article:

• Introduction
• Counterfeit Gemstones
• Precious and Semiprecious Gemstones
• Other Gemstones
• Diamond Cutting
• Gem Cutting
• Properties of Gems
• Bibliography

The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2024, Columbia University Press. All rights reserved.

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