Miersite Locality: Broken Hill Proprietary Mine (Proprietary Mine; BHP Mine), Broken Hill , Yancowinna County, New South Wales , Australia ( Locality at mindat.org ) Size: 4.9 x 3.2 x 2.8 cm. This piece features bright yellow, eye-visible miersite crystals, richly emplaced on ore matrix. This is a very rich specimen with unusual display aesthetics for this important and very rare silver/copper species (it is a startlingly simple silver and copper iodide, (Ag,Cu)I ). A very rich specimen, obviously validated, which I exchanged from the South Australian Museum last year (2008). The Museum label accompanies the piece. One seldom sees such a piece for sale (let alone, so well documented). — Photo: Robert M. Lavinsky · CC BY-SA 3.0
Miersite
Miersite is an IMA-recognized mineral species in the halide class, with the chemical formula AgI.
It crystallizes in the cubic crystal system (space group F-43m). It is a member of the Sphalerite structural group.
Key properties: Mohs hardness 2.5; specific gravity 5.64; Canary-yellow streak; Adamantine luster.
IMA symbol Mier, grandfathered status — known before the IMA’s founding, named in 1898.
A rare mineral found in the oxidized zone of some Pb–Zn–Cu–Ag deposits, especially in arid regions.
It is found associated with Iodargyrite, chlorargyrite, malachite, cerussite, cuprite (Broken Hill, Australia); gerhardtite, likasite (Likasi, Congo).
The mineral was named to honor Henry Alexander Miers (1858–1942), Professor of Mineralogy, Oxford University, Oxford, England.