brunogeierite (w. hematite and siderite)

TSNB663
Specimen
Feinglos, M.N.Gartrell, B.Innes, J.
Exhibit 1. Brunogeierite (w. hematite and siderite); 36 mm.
Exhibit 1. Brunogeierite (w. hematite and siderite); 36 mm.
Image Credit: Malcolm Southwood
Exhibit 2. 14 mm field of view.
Exhibit 2. 14 mm field of view.
Image Credit: Malcolm Southwood
Exhibit 3. 10 mm field of view.
Exhibit 3. 10 mm field of view.
Image Credit: Malcolm Southwood
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Specimen Title

brunogeierite (w. hematite and siderite)

Associated Minerals

hematite; quartz; siderite

Principal Mineral

Brunogeierite

Size

Miniature; 36mm

Location in the Mine

Second oxidation zone

Provenance

Innes, J.; Gartrell, B.; Feinglos, M.N.

Collection

MGMH; 2022.4.5962L

Entry Number

Specimen; TSNB663

Description

A shard of tarnished sulphide ore with quartz hosts a crust of minute (to circa 15 µm) pseudo-octahedral brunogeierite crystals, jet-black and with an adamantine lustre. Resting on the brunogeierite are platy individual crystals and books of red-brown hematite (to 2 mm) and sprays of elongated translucent red-brown siderite (with crystals to 4 mm).

The specimen was originally in the collection of John Innes, chief mineralogist at Tsumeb in the early 1980s. After Innes’s death it belonged to Blair Gartrell who sold it to Mark Feinglos in 1994. Brunogeierite was confirmed by Ernie Nickel at the CSIRO laboratories un Western Australia. There is no record of location in the mine but the pargenesis is definitive for the second oxidation zone.