Furutobeite

TSNB137
Mineral
Sulphide oresHypogene (?)Supergene (?)
Furutobeite: Striated needles and blades of furutobeite, with quartz and tennnatite. 10 mm field of view. MGMH Collection 2022.4.9135L.
Furutobeite: Striated needles and blades of furutobeite, with quartz and tennnatite. 10 mm field of view. MGMH Collection 2022.4.9135L.
Image Credit: Malcolm Southwood

Mineral Species

Furutobeite

Type Locality

No

Composition

(Cu,Ag)6PbS4

Crystal System

Monoclinic

Status at Tsumeb

Confirmed

Abundance

Very rare

Distribution

Sulphide ores

Paragenesis

Hypogene (?); supergene (?)

Entry Number

Species; TSNB137

General Notes

The occurrence of furutobeite at Tsumeb is noted in the Handbook of Mineralogy (https://www.bing.com/search?q=handbook+of+mineralgy&form=ANNTH1&refig=ee850fb2f9c8449997b9baea334e1a29; accessed December 2022). It forms small free-standing needle-like crystals on chalcocite or tennantite but is easily confused with betekhtinite, stromeyerite, stibnite, or even acicular chalcocite.


EDS investigation of a specimen in the Pinch Collection at Harvard University (MGMH 2020.7.3318), originally labelled as "stibnite" has shown it to be furutobeite (Frank Keutsch, pers. comm. to M. Southwood 2022).