aurichalcite

TSNB36

Species

Aurichalcite: Pale greenish-blue acicular crystals (to 1.5 mm) associated and intergrown with hemimorphite and hydrozincite. 30 mm field of view. MGMH Collection. 2022.4.5815L.
Aurichalcite: Pale greenish-blue acicular crystals (to 1.5 mm) associated and intergrown with hemimorphite and hydrozincite. 30 mm field of view. MGMH Collection. 2022.4.5815L.
Image Credit: Malcolm Southwood

Title

aurichalcite

Composition

(Zn,Cu2+)5(CO3)2(OH)6

Crystal System

Monoclinic

Status at Tsumeb

Confirmed

Abundance

Somewhat rare

Distribution

First and second (?) oxidation zones

Paragenesis

Supergene.

Type Locality

No

Entry Type

Species TSNB36

General Notes

Aurichalcite was relatively common in the upper portion of the first oxidation zone and particularly so in the open pit workings. It is, however, a very rare mineral at depth and its occurrence in the deeper oxidation zones is not unequivocal.

In the near-surface environment aurichalcite occurred in a distinctive paragenesis with hemimorphite and hydrozincite (Maucher 1908a,b; Gebhard 1999). Less commonly, it has been found associated with smithsonite. Typically, it occurs as pale green to sky-blue and turquoise-blue acicular crystals and crusts (Pinch and Wilson, 1977).

Associated Minerals

azurite; hemimorphite; hydrozincite; quartz; smithsonite

Pseudomorphs

Aurichalcite has been reported to form pseudomorphs after azurite (rare; Weber, 1977).