| Thortveitite | |
|---|---|
 Thortveitite | |
| General | |
| Category | Minerals |
| Formula | (Sc,Y)2Si2O7 |
| IMA symbol | Tvt1 |
| 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.5678
A transparent gem quality example was found in 2004, and reported in The Journal of Gemmology.9
References
References
- Warr, L.N. (2021). "IMA–CNMNC approved mineral symbols". Mineralogical Magazine. 85 (3): 291–320. Bibcode:2021MinM...85..291W. doi:10.1180/mgm.2021.43. S2CID 235729616.
- "Scandium". mindat.org. Retrieved 2025-05-29.
- Lowen, Eric. "Properties of Scandium". Stanford Advanced Materials. Retrieved Sep 24, 2024.
- Shelby Johnston. "Mineral Commodity Summaries 2025: Scandium" (PDF). National Minerals Information Center. U.S. Geological Survey. Retrieved 2025-05-29.
- "Thortveitite Mineral Data". webmineral.com. Retrieved 2021-05-03.
- "Thortveitite". www.mindat.org. Retrieved 2021-05-03.
- Bianchi, Riccardo; Pilati, Tullio; Diella, Valeria; Gramaccioli, Carlo Maria; Mannucci, Gregorio (1988-06-01). "A re-examination of thortveitite". American Mineralogist. 73 (5–6): 601–607. ISSN 0003-004X.
- Mineralien aus aller Welt. Walter Schumann. München. 1990. ISBN 978-3-405-14003-8. OCLC 610708490.
{{cite book}}: CS1 maint: location missing publisher (link) CS1 maint: others (link) - Chapman, R., Mercer, I.F., Rankin, A.H., Spratt, J. (2008). "Thortveitite – a new gemstone" (PDF). Journal of Gemmology. 31 (1): 1–6. Bibcode:2008JGem...31....1C. doi:10.15506/JoG.2008.31.1.1.
{{cite journal}}: CS1 maint: multiple names: authors list (link)