Chemistry:Thortveitite
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| Thortveitite | |
|---|---|
 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 |
| |re|er}} | 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]
See also
References
- ↑ Warr, L.N. (2021). "IMA–CNMNC approved mineral symbols". Mineralogical Magazine 85 (3): 291–320. doi:10.1180/mgm.2021.43. Bibcode: 2021MinM...85..291W.
- ↑ Scandium, MinDat.org, https://www.mindat.org/element/Scandium
- ↑ Lowen, Eric. "Properties of Scandium". https://www.stanfordmaterials.com/blog/an-overview-of-scandium.html.
- ↑ Shelby Johnston. "Mineral Commodity Summaries 2025: Scandium". U.S. Geological Survey. https://pubs.usgs.gov/periodicals/mcs2025/mcs2025-scandium.pdf.
- ↑ "Thortveitite Mineral Data". http://webmineral.com/data/Thortveitite.shtml#.YI_Dr7UzZEY.
- ↑ "Thortveitite". https://www.mindat.org/min-3950.html.
- ↑ Bianchi, Riccardo; Pilati, Tullio; Diella, Valeria; Gramaccioli, Carlo Maria; Mannucci, Gregorio (1988-06-01). "A re-examination of thortveitite" (in en). American Mineralogist 73 (5–6): 601–607. ISSN 0003-004X. https://pubs.geoscienceworld.org/msa/ammin/article-abstract/73/5-6/601/105009/A-re-examination-of-thortveitite.
- ↑ Mineralien aus aller Welt. Walter Schumann. München. 1990. ISBN 978-3-405-14003-8. OCLC 610708490.
- ↑ Chapman, R., Mercer, I.F., Rankin, A.H., Spratt, J. (2008). "Thortveitite – a new gemstone". Journal of Gemmology 31 (1): 1–6. doi:10.15506/JoG.2008.31.1.1. Bibcode: 2008JGem...31....1C. https://gem-a.com/images/Documents/JoG/JoG2009_31_5-8.pdf#page=3.
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