Gem Listings Main Page

...are bright, silvery, and metallic and are both attractive and unusual. However, they tarnish rather quickly and the surfaces turn a drab brown and lose their luster. Cut stones are...

Cutting Information for Specific Gemstones

...Imperfect Fracture: Subconchoidal Heat Sensitivity: Yes Birefringence (double… Dravite Tourmaline Facet / Faceting Information Dravite Tourmaline Color: Brown, yellow-brown, orange-brown and reddish-brown Moh’s Hardness: 7-7.5 Refractive Index: 1.616-1.652 Critical Angle:...

Page 1 of 2512345...1020...Last »