Azurite (w. malachite after azurite and bayldonite (?) after mimetite)

TSNB998
Specimen
Gruson, O.Kusche, A.Weinrich, D.
Exhibit 1. Azurite (w. malachite after azurite and bayldonite (?) after mimetite); 75 mm.
Exhibit 1. Azurite (w. malachite after azurite and bayldonite (?) after mimetite); 75 mm.
Image Credit: Paul Melville
Exhibit 2. 50 mm field of view.
Exhibit 2. 50 mm field of view.
Image Credit: Paul Melville
Exhibit 3. 50 mm field of view.
Exhibit 3. 50 mm field of view.
Image Credit: Paul Melville
Exhibit 4. Specimen label (Gruson).
Exhibit 4. Specimen label (Gruson).
Image Credit: Paul Melville
Exhibit 5. Specimen labels (Gruson and others).
Exhibit 5. Specimen labels (Gruson and others).
Image Credit: Paul Melville
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Specimen Title

Azurite (w. malachite after azurite and bayldonite (?) after mimetite)

Associated Minerals

arsentsumebite (?); bayldonite (?); malachite; mimetite

Principal Mineral

Azurite

Precursor Mineral

Azurite

Size

Cabinet; 75mm

Location in the Mine

First oxidation zone

Provenance

Kusche, A.; Gruson, O.; Weinrich, D.

Collection

Melville, P.

Entry Number

Specimen; TSNB998

Description

Bright, lustrous crystals of azurite, showing varying degrees of replacement by malachite (exhibits 1 and 2), on a matrix of bayldonite (?) and / or arsentsumebite (?), much of which is pseudomorphous after mimetite (Exhibit 3); (please note that the arsenates have not been analysed).

Acquired from Dan Weinrich who was dispersing specimens from the collection of the late Otto Gruson (1863-1929), a German industrialist and politician from the town of Magdeburg. Gruson's label is pasted into his card-tray (Exhibit 4) which accompanies the specimen, with other labels attached underneath (Exhibit 5). The text (in German) in the middle of Gruson's label (Exhibit 4) translates as follows and appears to provide a sense of the mode of occurrence of such specimens: 

"Occurrence: In the metasomatic copper-ore deposit, in cavities in lumps and nests of copper ore which occur together with sand in the limestone."

The labels on the underside of the card tray (Exhibit 5) indicate that Gruson acquired the specimen in August 1913, from Munich dealer Arthur Kusche. This provenance clearly dates the specimen to the upper portion of the first oxidation zone (i.e. 6 Level or above).