The colored gem tutorial at the Gemological Institute of America website is insightful, especially for people without any prior knowledge of gemstones.
Tutorial introduction page
It’s split into 7 steps with an interactive challenge to illustrate the point.
Challenge 1: Gems & Color
You can find the tutorial at http://www.gia.edu/
One of the books we publish is Gemstones – A Thai Love Story, which is part reference book, part eye candy. One of the things we’re doing to support the book is a Q&A session with the co-authors, Nora A. Phayackaporn and Jirayoot Wajanathawornchai.
I know very little about precious and semi-precious stones so I consider it a challenge to be moderating the Q&A.
Bluetoffee Team
