Thortveitite
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Mineral NameThortveitite
Chemical Formula(Sc,Y)₂Si₂O₇
Mohs Hardness6.5
Crystal Systemmonoclinic
Streak Colorwhite
Cleavagepoor/indistinct on {110}
Fractureconchoidal to uneven
Specific Gravity3.65
Colorsgray, greenish-gray, black, brownish-black, yellowish-brown, pinkish-brown
Transparencytranslucent to opaque
Type LocalityIveland, Aust-Agder, Norway
Mineral GroupSilicates (Sorosilicate)
Usesprimary ore of scandium, collector's mineral, aerospace alloys, fuel cells
Associated Mineralsquartz, feldspar, beryl, columbite, monazite, zircon, allanite, fergusonite, euxenite
Rarityrare
Description
Thortveitite is a rare scandium-yttrium sorosilicate mineral, typically forming prismatic to tabular crystals or massive aggregates, often exhibiting grayish to greenish-gray, brownish, or black hues.
Geological Context
It is primarily found in granite pegmatites, especially those enriched in rare-earth elements, forming during the late stages of magmatic crystallization.
