caledonite

TSNB67
Mineral
First oxidation zoneSupergene
Caledonite: Turquoise crystals (to 1 mm; XRD verified) in a vuggy matrix of cerussite and malachite. 34 mm specimen. M. Southwood Collection. MS2010.100.
Caledonite: Turquoise crystals (to 1 mm; XRD verified) in a vuggy matrix of cerussite and malachite. 34 mm specimen. M. Southwood Collection. MS2010.100.
Image Credit: Malcolm Southwood

Mineral Species

caledonite

Type Locality

No

Composition

Pb5Cu2(CO3)(SO4)3(OH)6

Crystal System

Orthorhombic

Status at Tsumeb

Confirmed

Abundance

Very rare

Distribution

First oxidation zone

Paragenesis

Supergene

Entry Number

Species; TSNB67

General Notes

The distribution of caledonite appears to have been limited to the upper portion of the first oxidation zone. It was first documented by Maucher (1908a) who described a paragenesis in which rare caledonite occurred as a minor component associated with brochantite, linarite, cerussite and malachite.


Bartelke (1976) stated that caledonite at Tsumeb has only been found in association with linarite and that the small, needle-like blue-green crystals commonly enclose a core of cerussite. Keller (1984) repeated this description and added that caledonite can be confused with posnjakite.