conichalcite (w. calcite)

TSNB585
Specimen
Bruce, I.Schneider, J.
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 (M. Southwood and P. Carr; unpublished).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 (M. Southwood and P. Carr; unpublished).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

Specimen Title

conichalcite (w. calcite)

Associated Minerals

calcite; cuprite; malachite

Principal Mineral

Conichalcite

Size

Thumbnail; 25mm

Provenance

Schneider, J.; Bruce, I.

Collection

Southwood, M.; MS2018.077

Entry Number

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.