duftite (w. dolomite and cerussite)

TSNB418

Specimen

Exhibit 1. Duftite (w. dolomite and cerussite); 75 mm.
Exhibit 1. Duftite (w. dolomite and cerussite); 75 mm.
Image Credit: Malcolm Southwood
Exhibit 2.
Exhibit 2.
Image Credit: Malcolm Southwood
Exhibit 3. Analytical data; duftite. (M. Southwood and P. Carr; unpublished).
Exhibit 3. Analytical data; duftite. (M. Southwood and P. Carr; unpublished).
Image Credit: Malcolm Southwood
Exhibit 4. Analytical data. Duftite on this specimen (blue circles) is calcium rich.
Exhibit 4. Analytical data. Duftite on this specimen (blue circles) is calcium rich.
Image Credit: Malcolm Southwood
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Title

duftite (w. dolomite and cerussite)

Principal Mineral

Duftite

Size

Cabinet; 75mm

Collection

Southwood, M. MS2015.078

Provenance

Schlegel, P.

Entry Type

Specimen TSNB418

Description

Framboidal aggregates of dark, olive-green duftite microcrystals associated with cream-coloured dolomite and crystals of colourless cerussite (to 7 mm), largely obscuring well-formed crystals of dark reddish-grey cuprite, peppered with tiny spherules of malachite (Exhibit 2).

There are apparently two generations of duftite. The crystallisation sequence appears to be: cuprite >> malachite >> duftite(i) >> cerussite >> dolomite >> duftite(ii). WDS analysis confirms that the second generation duftite is Ca-rich (exhibits 3 and 4), with moderate compositional variation; the Ca content ranges from circa 31.5 to 41.7 mol %.

The specimen was purchased in 2015 from German dealer Peter Schlegel.

Associated Minerals

cerussite; cuprite; dolomite; malachite