Freibergite Subgroup coated by Stannite

Item Description

These wonderful Freibergite specimens came out in the late 1990s, and were short-lived. I think only a handful of pockets were found, and to the best of my knowledge, no more specimens have been seen. This attractive toenail sized piece hosts several fine quality, sharp, well-formed, metallic gray, tetrahedral crystals of the silver, copper, antimony sulfosalt, Freibergite (more properly the Freibergite Subgroup since the specific species isn't known) measuring up to 2.2 cm on edge, sitting on matrix. The Freibergites have a minor epitaxial coating of Stannite (confirmed through analysis), giving them an almost chatoyant luster on the surface. There is a bit of peacock-colored iridescence on the matrix, due to a thin layer of Bornite. The Freibergites are in good shape, but they are contacted in a few spots on the lower sides, so they are not pristine. A very attractive display piece of this hard to find material.
From the collection of Colin Manlove, with a classic hand-written label from the well-known Bolivian mineral expert, Alfredo Petrov.