World of Colored Gems
Explore the diversity of colored gemstones beyond the Big Three — from spinels and garnets to phenomenal gems and modern discoveries reshaping the market.
intermediateRuby: The King of Gemstones
The geology, history, and grading of the world's most valued colored stone
Sapphire Beyond Blue: A Spectrum of Colors
The extraordinary color range of corundum — from padparadscha to color-change sapphire
Emerald: The Green Fire
The geology, grading, and cultural significance of the world's premier green gemstone
Tourmaline: The Rainbow Gem
One mineral group, every color — from Paraiba neon to watermelon slices
Spinel: The Great Impostor Redeemed
Once mistaken for ruby, spinel has emerged as one of the most desirable collector gems
Garnet: More Than Deep Red
The extraordinary diversity of the garnet group — from tsavorite green to color-change blues
Tanzanite, Alexandrite, and Other Collector Stones
Rare and phenomenal gems that captivate collectors with unique optical properties
Opal: Play of Color and Formation
How silica spheres create nature's most dynamic gemstone