Science, tools, identification, treatment, valuation & grading of gems
Science, identification, classification, and testing of minerals
Gemstone jewelry settings, metals, tools, cutting & faceting stones
List of all gemstones from A-Z with in-depth information for each
Thousands of gem photos searchable by various properties.
Everything you need to know about buying your perfect diamond
Learn more about these popular gemstones, their meaning & about buying birthstone jewelry
Price guidance on over 70 types of gemstones
In-depth guides to quality factors of the 40 most popular gemstones
Tanzanite has had a rapid rise to prominence among jewelers and gem enthusiasts. Although naturally reddish brown, this transparent zoisite variety achieves a stable, beautiful blue to violet color with heat treatments.