- Colquechaca, Bolivia
- Miniature, 4.6 x 4.4 x 2.7 cm
- Ex. Dr. Mark Feinglos
An incredibly rich specimen of almost SOLID argyrodite, one of the rarest of silver species because of its association with germanium (Ag8GeS6). Not often seen in dealers stocks, this rare silver, germanium, sulfide manifests here as "relatively beautiful" rosettes of black crystals atop massive, lustrous ore. The largest rosette is 1.5 cm across, although it is of course composed of smaller crystals within. This is an incredibly rich sample of the species, from one of its most important locales! Most importantly, it is validated up and down by the previous owner. These specimens are historic, with surviving pieces having been found on just a few occasions over hundreds of years of mining here. It was only identified in the late 1880s once germanium itself was better understood and analysible. This particular piece is the richest I have seen for sale or owned, and was exchanged to me about 6 years ago by Dr Mark Feinglos, who had long owned it in his Collection. He got it from. A. L. McGuiness. I sold it to another collector and recently got it back, to re-offer. It comes with XRD analysis and labels.