Kegelite

phyllosilicate

Tsumeb

Formula: Pb42Si4O10(SO4)(CO3)2(OH)4
Phyllosilicate (sheet silicate), lead mineral
Specific gravity: ~4.5 (AM 75.702-704)
Colour: Colourless
Solubility: Insoluble in hydrochloric acid (AM 61.175-176)
Environments

Hydrothermal environments

Kegelite is a rare supergene lead mineral.

At the type locality, the Tsumeb Mine, Oshikoto Region, Namibia, kegelite occurs in a deep oxidation zone in a polymetallic hydrothermal mineral deposit, intergrown with hematite and mimetite (Dana) and associated with quartz, galena, leadhillite, anglesite, fleischerite, melanotekite and alamosite (HOM, Mindat, AM 75.702-704).

At Wanlockhead, Dumfries and Galloway, Scotland, UK, kegelite has been found on the spoil heaps on a small block with an exterior of weathered hemimorphite encrusted with minute descloizite crystals together with a few vanadinite crystals. The interior of the block has kernels of residual galena and mudstone surrounded by leadhillite, cerussite and quartz. Kegelite was embedded in leadhillite and intimately associated with cerussite (JRS 8.110-111).

Common impurities: Cu,H2O

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