conichalcite (w. calcite)

TSNB585

Specimen

Exhibit 1. Conichalcite (w. calcite); 25 mm.
Exhibit 1. Conichalcite (w. calcite); 25 mm.
Image Credit: Malcolm Southwood
Exhibit 2. Analytical data; conichalcite. (M. Southwood and P. Carr; unpublished).
Exhibit 2. Analytical data; conichalcite. (M. Southwood and P. Carr; unpublished).
Image Credit: Malcolm Southwood
Exhibit 3. Analytical data. Conichalcite on this specimen (blue circles) is very close to end-member composition.
Exhibit 3. Analytical data. Conichalcite on this specimen (blue circles) is very close to end-member composition.
Image Credit: Malcolm Southwood
Thumbnail by 1Thumbnail by 2Thumbnail by 3

Title

conichalcite (w. calcite)

Principal Mineral

Conichalcite

Size

Thumbnail; 25mm

Collection

Southwood, M. MS2018.077

Provenance

Schneider, J.; Bruce, I.

Entry Type

Specimen TSNB585

Description

A hemispherical crust of botryoidal, apple-green conichalcite associated with malachite and two generations of calcite on massive cuprite. The cuprite is overgrown by a thin veneer of malachite, followed by a layer of colourless-white first generation calcite, botryoidal conichalcite and finally a peppering of individual and intergrown colourless-white calcite rhombs (to circa 0.5 mm). EMPA-WDS analysis (exhibits 2 and 3) shows the conichalcite to be Zn-bearing, but quite close to ideal end-member composition.

The specimen was acquired from Ian Bruce in 2018 and was formerly in the collection of John Schneider. The location in the mine is not recorded.

Associated Minerals

calcite; cuprite; malachite