Bayldonite (w. zincolivenite and schultenite)

TSNB601
Specimen
Pinch, W.W.
Exhibit 1. Bayldonite (w. zincolivenite and schultenite); 72 mm.
Exhibit 1. Bayldonite (w. zincolivenite and schultenite); 72 mm.
Image Credit: Malcolm Southwood
Exhibit 2. 35 mm field of view.
Exhibit 2. 35 mm field of view.
Image Credit: Malcolm Southwood
Exhibit 3. Specimen label (Bill Pinch).
Exhibit 3. Specimen label (Bill Pinch).
Image Credit: Malcom Southwood
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Specimen Title

Bayldonite (w. zincolivenite and schultenite)

Associated Minerals

schultenite; tennantite-(Zn); zincolivenite

Principal Mineral

Bayldonite

Size

Cabinet; 72mm

Location in the Mine

Second oxidation zone; 28 Level (?)

Provenance

Pinch, W.W.

Collection

MGMH; 2020.7.700

Entry Number

Specimen; TSNB601

Associated Minerals

schultenite; tennantite-(Zn); zincolivenite

Description

A tennantite-rich massive sulfide matrix, thickly encrusted with zincolivenite forming blocky crystals (to 12 mm) with pristine striated prism faces but distinctive, ragged-looking (multiply terminated) pinacoids. A little colourless-white schultenite is intergrown with the zincolivenite. Pseudo-scalenohedral crystals of greenish-black, adamantine bayldonite (to 5 mm) rest on the zincolivenite (Exhibit 2).

The specimen is from the Pinch Collection and Pinch's label (Exhibit 3) notes the size of the bayldonite crystals as remarkable for the species. There is no recorded provenance but, according to Key (1977), this material was recovered from 28 Level in the second oxidation zone in the early 1970s. The finest crystals from this occurrence reached 10 mm in length and are considered best of species. Cesbron and Vachey (1974) recognised that the pseudo-scalenohedral crystals are in fact trillings "...built in fact from three crystals in twin position."