Thortveitite | |
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![]() Thortveitite | |
General | |
Category | Minerals |
Formula | (Sc,Y)2Si2O7 |
IMA symbol | Tvt [1] |
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 rare mineral consisting of scandium yttrium silicate (Sc,Y)2Si2O7. It is the most widespread scandium mineral, [2] but natural thortveitite is not widely exploited as a source of scandium metal. Most scandium is derived from mine tailings, which can include thortveitite. [3] Thortveitite mining in the United States ceased in 1969. [4]
Occurrence is in granitic pegmatites. It was named after Olaus Thortveit, a Norwegian engineer. It is grayish-green, black or gray in color. [5] [6] [7] [8]
A transparent gem quality example was found in 2004, and reported in The Journal of Gemmology. [9]
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