lammerite (w. chalcanthite and anhydrite)

A shard of tennantite-rich sulphide ore, partly encrusted with bright blue chalcanthite crystals. Beneath the chalcanthite (which has been partly removed on this specimen) are radial sprays of very dark green - almost black - lammerite crystals (to circa 1 mm; Exhibit 2), associated with pale green fibrous crystals of anhydrite resting directly on the sulphide.

The specimen was formerly in the collection of Bill Pinch (Exhibit 3), who obtained it from TCL mineralogist John Innes. Innes' handwritten label (Exhibit 4) indicates that it was collected in the North East Stope on 35 Level in 1980, a discovery documented by Keller (1981) and by Keller and Bartelke (1982). The paragenesis also includes leightonite, although it has not been identified on this specimen. Pinch recalled that he spent three days working with a beaker of water and an eye-dropper to remove, very gently, sufficient of the chalcanthite to expose the lammerite (pers. comm. to M. Southwood, 2015).

anhydrite; chalcanthite; quartz; tennantite-(Zn)