Ktenasite coating Calcite (VERY RARE locality specimen)

Item Description

Ktenasite is a rare hydrated Zn-Cu-sulfate species, which is not often seen represented in display quality specimen. This mineral is extremely rare from the historic Joplin Field in Missouri, and we've only had a few examples to offer over the years. This showy small cabinet features a thin layer of light blue-green colored Ktenasite, overgrowing soft yellow colored scalenohedral Calcites, sitting atop sharp, well-formed crystals of pseudo-octahedral Chalcopyrite with an unusual brownish coating/oxidation on the surface, sitting atop massive Sphalerite. The largest Calcite measures 4.0 cm. No major damage that I can see, only a small nick on the back of one of the terminations of the Calcites, otherwise the piece is in great shape, though the matrix is obviously contacted where the piece was removed from the pocket wall. These pieces are extremely hard to find, and this is certainly one of the best examples we've had to offer in the auctions, most notably because there are multiple Calcite crystals present on the specimens, where others only featured a single Calcite crystal.