A very small green crystal of fahleite (a Zn-Ca-Fe arsenate), an extremely rare Tsumeb mineral only known from this locality worldwide, which is of course the type locality (Tsumeb Mine, Otavi Highlands, Namibia). The species was labeled as RRR! in Gebhard Tsumeb II book. — Photo: David Hospital · CC BY-SA 4.0
Fahleite
Fahleite is an IMA-recognized mineral species in the arsenate class, with the chemical formula CaZn₅Fe³⁺₂(AsO₄)₆·14H₂O.
It is a member of the Smolyaninovite structural group.
Key properties: specific gravity 3.08; Silky or pearly luster; optically biaxial.
IMA symbol Fhl, IMA status: approved, named in 1982.
On oxidized tennantite–chalcocite ore from a deep oxidized zone of a dolostone-hosted hydrothermal polymetallic ore deposit.
It is found associated with Lavendulan, cuprian adamite, conichalcite, tsumcorite, tennantite, chalcocite, quartz, calcite, gypsum.
In honor of Rolf Fahle (1943–), Munich, Germany, mineral dealer specializing in Tsumeb minerals, who supplied the specimen from which the species was described.