Kegelite
Phyllosilicate mineral
From Wikipedia, the free encyclopedia
Kegelite is a complex silicate mineral with formula Pb8Al4Si8O20(SO4)2(CO3)4(OH)8.
| 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] |
It was first described in 1975 for an occurrence in the Tsumeb Mine, Tsumeb, Otjikoto Region, Namibia and named for Friedrich Wilhelm Kegel (1874–1948), 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]
