Azurite (w. otavite, cerussite, malachite, rosasite and smithsonite)

TSNB909
Specimen
Berger, A.Bruce, I.Lammer, F.
Exhibit 1. Azurite (w. otavite, cerussite, malachite, rosasite and smithsonite); 120 mm.
Exhibit 1. Azurite (w. otavite, cerussite, malachite, rosasite and smithsonite); 120 mm.
Image Credit: Malcolm Southwood
Exhibit 1. Azurite (w. otavite, cerussite, malachite, rosasite and smithsonite); 120 mm.
Exhibit 1. Azurite (w. otavite, cerussite, malachite, rosasite and smithsonite); 120 mm.
Image Credit: Malcolm Southwood
Exhibit 3. 35 mm field of view.
Exhibit 3. 35 mm field of view.
Image Credit: Malcolm Southwood
Exhibit 4. 45 mm field of view.
Exhibit 4. 45 mm field of view.
Image Credit: Malcolm Southwood
Exhibit 5. 40 mm field of view.
Exhibit 5. 40 mm field of view.
Image Credit: Malcolm Southwood
Exhibit 6. Specimen label (Anton Berger).
Exhibit 6. Specimen label (Anton Berger).
Image Credit: Malcolm Southwood
Exhibit 7. Specimen label (Franz Lammer).
Exhibit 7. Specimen label (Franz Lammer).
Image Credit: Malcolm Southwood
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Specimen Title

Azurite (w. otavite, cerussite, malachite, rosasite and smithsonite)

Associated Minerals

cerussite; dolomite (?); greenockite (?); malachite; otavite; rosasite; smithsonite

Principal Mineral

Azurite

Precursor Mineral

Azurite

Size

Cabinet; 120mm

Location in the Mine

First oxidation zone

Provenance

Berger, A.; Lammer, F.; Bruce, I.

Collection

Southwood, M.; MS2015.080

Entry Number

Specimen; TSNB909

Description

A matrix of feldspathic sandstone (?), with disseminated sulphides and vugs lined with very pale green smithsonite. The display face comprises a layered carbonate paragenesis commencing with a thin crust of white dolomite (?), succeeded by a druse of very pale green smithsonite rhombs, the outer layer of which is coloured yellow-orange due to minute inclusions of what is possibly greenockite (?) (Exhibit 3). The smithsonite is extensively encrusted with pearly-white otavite (EDS confirmed*; Frank Keutsch, Harvard University 2025) which is in turn partly encrusted with c.1 mm spherules of rosasite, densely aggregated in the lower portion of the specimen (as seen in Exhibit 1).  Colourless-white twinned cerussite crystals (to c. 8 mm; Exhibit 4) are perched on both the rosasite and the otavite. Azurite is the youngest mineral in the paragenesis, but the large azurite crystal comprises a second generation shell of azurite over a pseudomorph of malachite after azurite (Exhibit 5). The paragenesis therefore appears to be:  dolomite (?) >> smithsonite >> greenockite (?) >> otavite >> rosasite >> cerussite >> azurite (i) >> malachite >> azurite (ii).  


Both the otavite and the cerussite fluoresce strongly under short wavelength ultraviolet radiation; the otavite orange-yellow and the cerussite orange.

The specimen was originally in the private collection (# 561) of Austrian mineral dealer Anton Berger (1870-1956; Exhibit 6). It belonged subsequently to Franz Lammer (1914-1997), of Leoben, Germany (# 2713) whose collection was dispersed by Ian Bruce in 2015, from whom the specimen was purchased.  At least four specimens from this distinctive occurrence are known. One of them, MGMH 93543, in the collections at Harvard University bears comparison (see TSNB701). The vintage of these specimens confirms a first oxidation zone origin although the exact location in the mine is not known.
  
*EDS confirmation of otavite was on material sampled from specimen MGMH 93543 (see TSNB701).