Gemstone hardness may vary a bit within a species. However, kyanite is unusual in that its hardness may vary tremendously, from 4 to 7.5, within a single crystal. Faceters rarely cut this stone. Kyanite and quartz, Barra de Salinas, Coronel Murta, Jequitinhonha Valley, Minas Gerais, Brazil. Photo by Géry Parent. Licensed under CC By-ND 2.0.
Opaque Blue Kyanite Specimen from Brazil
Gemstone hardness may vary a bit within a species. However, kyanite is unusual in that its hardness may vary tremendously, from 4 to 7.5, within a single crystal. Faceters rarely cut this stone. Kyanite and quartz, Barra de Salinas, Coronel Murta, Jequitinhonha Valley, Minas Gerais, Brazil. Photo by Géry Parent. Licensed under CC By-ND 2.0.
Article: Gemstone Hardness and Wearability
Credit: Géry Parent
| Gemstone | Kyanite |
| Natural or man made | Natural |
| Origin | Brazil |
| Origin details | Barra de Salinas, Coronel Murta, Jequitinhonha Valley, Minas Gerais |
| Gem State | Specimen |
| Color | Blue |
| Transparency | Opaque |