*** Welcome to piglix ***

Thortveitite

Thortveitite
Thortveitite-ea14a.jpg
Thortveitite
General
Category Mineral
Formula
(repeating unit)
(Sc,Y)2Si2O7
Strunz classification 9.BC.05
Crystal system Monoclinic
Crystal class Prismatic (2/m)
(same H-M symbol)
Space group C2/m
Identification
Mohs scale hardness 5-6
Luster vitreous
Streak gray
Specific gravity 3.3-3.8

Thortveitite is a mineral consisting of scandium yttrium silicate (Sc,Y)2Si2O7. It is the primary source of scandium. Occurrence is in granitic pegmatites. It was named after Olaus Thortveit, a Norwegian engineer. It is grayish-green, black or gray in color.

A transparent gem quality example was found in 2004, and reported in "The Journal of Gemmology", 2008 Volume 31.



...
Wikipedia

...