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FTC - http://www.ftc.gov/bcp/guides/jewel-gd.htm
FTC Guides for jewelry and precious metals. |
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The Image - http://www.theimage.com/
Mineral and gemstone galleries. Physical properties and historical facts for minerals and gemstones. |
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Gems and Precious Stones - http://ist-socrates.berkeley.edu/~eps2/
An on-line gem and jewelry course at UC Berkeley. |
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Gem Hut - http://www.gemhut.com/
Hundreds of descriptions for gems, minerals, and rare metals. Pictures, hardness, and composition. |
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NOVA - http://www.pbs.org/wgbh/nova/diamond/gemprimer.html
Gemstone primer with photos and vital information regarding gemstones. |