Mineralpedia Details for Keystoneite
Keystoneite
- Formula
- H0.8Mg0.8(Ni,Fe3+,Mn)2(Te4+O3)3ยท5H2O
- Crystal System
- Hexagonal
- Crystal Habit
- Acicular, Radial
- Cleavage
- None, None, None
- Luster
- Adamantine
- Color
- golden yellow, orange yellow
- Class
- Hexagonal - Dipyramidal
- Hardness
- -
- WebMineral
- View Keystoneite
- Mindat
- View Keystoneite
Keystoneite from McAlpine mine, Tuolumne Co., California, United States
Yellow aicular (?) crystals, very minute, on Quartz and associated with silvery, dull grey, sectile Hessite and Gold. These minerals occupy an area only about 3 or 4mm wide. There is likely more here than meets the eye. It's a cool specimen. Very rare mineral occuring in two localities worldwide per Mindat.org.
Click thumbnail images for larger view.
