Edwardsite

TSNB115
Mineral
UndeterminedSupergene

Mineral Species

Edwardsite

Type Locality

No

Composition

Cu3Cd2(SO4)2(OH)6 4H2O

Crystal System

Monoclinic

Status at Tsumeb

Believed valid

Abundance

Extremely rare

Distribution

Undetermined

Paragenesis

Supergene

Entry Number

Species; TSNB115

General Notes

The occurrence of edwardsite at Tsumeb was reported by Joy Désor in April 2020, based on analysis by microdiffraction, single crystal XRD, EDS and Raman spectroscopy (Joy Désor - New minerals for the Tsumeb mine, Namibia (mindat.org); accessed October 2022).

Edwardsite is one of several cadmium-bearing minerals identified by Désor in a large specimen of germanite ore (with chalcocite, galena and sphalerite) containing vugs hosting cerussite, galloplumbogummite and pyromorphite. The paragenesis also includes niedermayrite, lauraniite, lazaridisite and otavite.

Edwardsite occurs as greenish-blue or pale blue arrow-shaped crystals to 50 μm and as coatings comprising intergrowths of poorly defined crystals. Ktenasite, lauraniite and niedermayrite are common close associates.

Associated Minerals

cerussite; chalcocite; galena; galloplumbogummite; germanite; gunningite; ktenasite; lauraniite; lazaridisite; niedermayrite; otavite; pyromorphite; quartz; sphalerite; voudourisite (?)