Using the Aurora Collection of 260 fancy colour diamonds as its foundation, "Collecting and Classifying Coloured Diamonds, An Illustrated Study of the Aurora Collection", explores the gamut of colours displayed by diamonds in nature and, in a format for both the layperson and the expert, investigates how diamond colours are perceived, measured, and classified. "Forever Brilliant, The Aurora Collection of Colored Diamonds" catalogues the world's most famous diamond collection consisting of 260 natural colored diamonds which have been on display at the American Museum of Natural History in New York since 1989.
Many of the old lapidaries (writers who wrote about gemstones) attributed different spiritual and medical properties to different stones. The site has many texts even from before the 16th century. Great resource in addition to our library of old books
ACS (American Chemical Society) cover story (article by Amanda Yarnell) on how heat treatment and chemical additives can make mundane stones look they are exclusive fancy/colored/rare diamonds/gems. A MUST READ before purchasing diamonds or gemstones!
Extensive calculator for estimating weight of gems and diamonds which are already set in jewelry. You need to take pretty exact measurements and know the type of cut as well as the depth of the stone which can be difficult to measure if the stone is already set. Still quite an interesting tool.
The private website of Richard Hughes containing dozens of articles on rubies, sapphires, and the mining areas where they are found. Richard Hughes, a gemologist working at the AGTA-GTC gem lab, is considered one of the best experts in the world on rubies and sapphires.