Kegelite
| Kegelite | |
|---|---|
 Kegelite microcrystals with a 1 cm. siderite crystal at right, from the type locality | |
| General | |
| Category | Phyllosilicate minerals |
| Formula | Pb8Al4Si8O20(SO4)2(CO3)4(OH)8 |
| IMA symbol | Keg[1] |
| Strunz classification | 9.EC.80 |
| Dana classification | 71.05.01.01 |
| Crystal system | Monoclinic Unknown space group |
| Identification | |
| Color | Colorless to white |
| Crystal habit | Pseudohexagonal plates in spherical aggregates |
| Cleavage | Perfect on {100} |
| Tenacity | Extremely flexible |
| Mohs scale hardness | no data |
| Luster | Vitreous |
| Streak | White |
| Diaphaneity | Transparent to translucent |
| Specific gravity | 4.5 |
| Optical properties | Biaxial (-) |
| Refractive index | n = 1.81 parallel to {100} |
| References | [2][3][4] |
Kegelite is a complex silicate mineral with formula Pb8Al4Si8O20(SO4)2(CO3)4(OH)8.
It was first described in 1975 for an occurrence in the Tsumeb Mine, Tsumeb, Otjikoto Region, Namibia and named for Friedrich Wilhelm Kegel (?-1948), Director of mining operations at Tsumeb.[2][4] It occurs in a deeply oxidized polymetallic ore deposits in Tsumeb. Associated minerals include quartz, galena, mimetite, hematite, leadhillite, anglesite, fleischerite, melanotekite and alamosite.[2] It has also been reported from the Zeehan district in Tasmania and from Tune, Sarpsborg, Østfold, Norway.[4]
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.
- ^ a b c http://rruff.geo.arizona.edu/doclib/hom/kegelite.pdf Handbook of Mineralogy
- ^ http://www.webmineral.com/data/Kegelite.shtml Webmineral data
- ^ a b c http://www.mindat.org/min-2175.html Mindat.org
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