Chalcopyrite with Calcite

Item Description

Here is a very rare specimen of Chalcopyrite from Tsumeb. Some collectors believe that Tsumeb just doesn't have Chalcopyrite, along with a few other sulfides and sulfosalts: however, over the decades, specimens of select species show up in different collections and we realize that so much has been missed. The mine operated for 100 years and more. Sulfides are always oddly rare here, and who knows what may have existed once, before complex replacements and events took place underground to change the original sulfides into the beautiful secondary minerals we see more often from the mine. This unique piece consists of unusual metallic yellow-green Chalcopyrite in an altered, gray limestone matrix, and then more importantly for the collector as dozens of 0.5 to 1.3 cm digitations (finger like growths) that are prominent around much of the piece in the front. These organic like growths of Chalcopyrite exhibit a colorful blue to purple patina on their surfaces due to oxidation reactions (as opposed to pyrite, which is more common here) and are admixed with some Calcite. Larger, lustrous, transparent to translucent Calcite discs to 2 cm are clustered at the top of the piece. This is a very unusual piece from Tsumeb! It is a cabinet piece, with huge display value as it stands out not for the species itself, but simply to the eye for its unique visual quality. We have never seen another beyond thumbnail size. Erika was literally the biggest buyer of Tsumeb for many years. She obtained entire old collections. This is one of those Tsumeb oddities that makes a collection by its uniqueness. Impossible to value as we have seen no comparables.