Feature Gems & Gemology, Spring 1992, Vol. 28, No. 1

Gem-Quality Green Zoisite

A new transparent, gem-quality green zoisite has been discovered in the Merelani Hills of mineral-rich Tanzania. The gemological properties are identical to those known for violetish blue tanzanite. The main differences are the pleochroic colors and the presence of chromium lines in the absorption spectrum of the green material. Chemical analyses demonstrated the presence of varying amounts of chromium and vanadium relative to the saturation of green.