Category: Featured Articles

Diamond Market

Vegas was all about fancy color diamonds. Demand for melee and single stones in color is strong. Colorless diamond prices are stable despite rising cost of rough. Manufacturers are angry at mining companies for the…

The Black Gem Challenge

Black stones have been in vogue for some time even sold as loose stones on the TV or Internet. See figure 1. While originally these may have been black diamonds set in expensive jewelry, we…

In The Land of Zultanite

The Milenyum Diaspore mine is the world’s only known deposit of gem quality Diaspore. The mineral diaspore is mined in many locations around the world, but no other are currently known that produce this beautiful…

The Colors of Corundum

Transparent colored gemstones are loved for their beautiful colors. How they absorb the visible light that passes through them determines their color (Figure 1). The study of light absorption by materials is called spectroscopy. Because…