Gemstone

The Amber Ranch
Dominican rough blue amber for jewellers and collectors.
http://www.ambarazul.com

Bluechart
A gem identification chart for $18.
http://www.gembluechart.com/

Caribbean Gemological Institute
Caribbean jewelers organization includes jewelry, shopping and travel tips..
http://www.carigem.org/

Dan Dennis
Author of "Gems: A Lively Guide for the Casual Collector."
http://www.dandennis.com/

Florida Gold Coast & Mineral Society
Gold and Mineral Society in Florida.
http://www.fgcgms.com/

FTC
FTC Guides for jewelry and precious metals.
http://www.ftc.gov/bcp/guides/jewel-gd.htm

Gem Hut
Hundreds of descriptions for gems, minerals, and rare metals. Pictures, hardness, and composition.
http://www.gemhut.com/

Gemology Tools
Software for the professional gemologist or gemology student/enthusiast.
http://www.gemologytools.com

Gems and Precious Stones
An on-line gem and jewelry course at UC Berkeley.
http://ist-socrates.berkeley.edu/~eps2/

Gemstone Forecaster Newsletters
Analyzes Burma ruby and sapphire gems and collector gemstone markets.
http://www.preciousgemstones.com/Forecasters.html

GeoNord
Gem and mineral site from Sweden.
http://www.geonord.org/

The Image
Mineral and gemstone galleries. Physical properties and historical facts for minerals and gemstones.
http://www.theimage.com/

National Gemstone
Introduction to collecting and investing in gemstones and colored diamonds, with descriptions of the types most widely traded.
http://www.preciousgemstones.com/GEMCOLLECTING.HTML

NOVA
Gemstone primer with photos and vital information regarding gemstones.
http://www.pbs.org/wgbh/nova/diamond/gemprimer.html

Secret Jewelry Collection
A Japanese collector's site of jewelry, minerals and gemstones.
http://www.geocities.jp/senribb/jewels/

Secrets of the Gem Trade. The Connoisseur's Guide To Precious Gemstones.
A new gem book by R. W. Wise.
http://secretsofthegemtrade.com/

University of Texas Gem Class
Gem and Mineral class at the University of Texas, Austin.
http://www.geo.utexas.edu/courses/347k/redesign/Gem_Notes/gemnote_triple_frame.htm