Mineral Species
Famatinite
Type Locality
No
Composition
Cu2CuSbS4
Crystal System
Tetragonal
Status at Tsumeb
Questionable
Entry Number
Species; TSNB126
General Notes
The occurrence of famatinite at Tsumeb is questionable even though it was alluded to very early in the mine’s operational history by Maucher (1908) who described "stibioluzonite or arsenic-rich famatinite", a mineral intermediate in composition between famatinite and luzonite (Cu2CuAsS4) as an apparently common constituent of the early ore samples available to him. His identification was based on a combination of optical properties and blowpipe analysis.
Schneiderhöhn and Ramdohr (1931) also considered stibioluzonite as an arsenic-bearing variety of famatinite; however, Strunz (1959) used the name stibioluzonite as a pseudonym of famatinite.
Bartelke (1976) made no mention of famatinite but noted the presence of luzonite at Tsumeb with small included amounts of stibioluzonite.
Pinch and Wilson (1977) described famatinite as "Massive, sooty black metallic. Probably part of a series to luzonite." but it seems unlikely that this description could have been based on verified material from Tsumeb.
Keller (1984) noted that luzonite is now a rare mineral at Tsumeb and that it possibly forms mischkristalle [= mixed crystals] with famatinite. Lombaard et al. (1986) listed famatinite as an "extremely rare" mineral at Tsumeb. Gebhard (1999) noted merely that famatinite has been observed in polished sections by ore microscopy. None of these more recent authors provided analytical data to support the identification of famatinite.
Hughes (1987) considered the occurrence of famatinite at Tsumeb questionable. He noted that several rare ore minerals provisionally identified by optical means, including famatinite, were not further substantiated and that Bruno Geier (chief mineralogist at Tsumeb between 1952 and 1972) "… revised a number of his early, tentative identifications as more data became available". Unfortunately, most of these revisions were recorded in unpublished TCL reports which are no longer available.
Questionable status is retained for famatinite pending reliable confirmation.
Associated Minerals
germanite (?); luzonite (?)
