Image Credit: Malcolm Southwood
Specimen Title
malachite after copper
Associated Minerals
calcite; cuprite
Principal Mineral
Precursor Mineral (Uncertain)
Size
Cabinet; 67mm
Location in the Mine
First oxidation zone
Provenance
Palache, C.
Collection
MGMH; 87543
Entry Number
Specimen; TSNB691
Description
A cavernous mass of malachite, as dendritic strings of botryoidal aggregates (to 3 mm), presumably pseudomorphs after native copper (?). A few of the tiny botryoids retain relict shape of the rhombic dodecahedron, indicating that the malachite is at least partly replacing cuprite which was in turn replacing copper. Consistent with this observation, a broken dendrite on the reverse of the specimen reveals cuprite in the core.
A druse of minute, colourless calcite rhombohedrons covers the malachite on part of the specimen providing a sparkly lustre.
The specimen is from the collection purchased by Charles Palache during his visit to Tsumeb in December 1922, which dates it to the upper part of the first oxidation zone (i.e. 8 Level or above).
