powellite
≈ 3 min read
Names in other languages
- capowel·lita
- Englishpowellite
- FrançaisPowellite
- NederlandsPowelliet
- DeutschPowellit
- PolskiPowellit
- УкраїнськаПовеліт
- فارسیپوولیت
Article bodies are English and are not machine-translated. A name in another language is not a translation of the article.
Powellite is a calcium molybdate mineral with formula CaMoO 4 . Powellite crystallizes with tetragonal – dipyramidal crystal structure as transparent adamantine blue, greenish-brown, yellow-to-grey typically anhedral forms. It exhibits distinct cleavage, and has a brittle-to-conchoidal fracture. It has a Mohs hardness of 3.5 to 4 and a specific gravity of 4.25. It forms a solid solution series with scheelite (calcium tungstate, CaWO 4 ). It has refractive index values of n ω =1.974 and n ε =1.984. Powellite was first described by William Harlow Melville in 1891 for an occurrence in the Peacock Mine, Adams County, Idaho, and named for American explorer and geologist, John Wesley Powell (1834–1902). It occurs in hydrothermal ore deposits of molybdenum within the near-surface oxidized zones. It also appears as a rare mineral phase in pegmatite, tactite and basalt. Minerals found in association with powellite include molybdenite, ferrimolybdite, stilbite, laumontite and apophyllite.
Powellite is a calcium molybdate mineral with formula CaMoO 4 . Powellite crystallizes with tetragonal – dipyramidal crystal structure as transparent adamantine blue, greenish-brown, yellow-to-grey typically anhedral forms. It exhibits distinct cleavage, and has a brittle-to-conchoidal fracture. It has a Mohs hardness of 3.5 to 4 and a specific gravity of 4.25. It forms a solid solution series with scheelite (calcium tungstate, CaWO 4 ). It has refractive index values of n ω =1.974 and n ε =1.984. Powellite was first described by William Harlow Melville in 1891 for an occurrence in the Peacock Mine, Adams County, Idaho, and named for American explorer and geologist, John Wesley Powell (1834–1902). It occurs in hydrothermal ore deposits of molybdenum within the near-surface oxidized zones. It also appears as a rare mineral phase in pegmatite, tactite and basalt. Minerals found in association with powellite include molybdenite, ferrimolybdite, stilbite, laumontite and apophyllite.
References
Palache, C., H. Berman, and C. Frondel (1951) Dana’s System of Mineralogy, (7th edition), v. II, pp. 1079–1081.
External links
Text derived from https://en.wikipedia.org/w/index.php?oldid=1177282012 under CC BY-SA 4.0; modifications have been made.