Cadmium Smithsonite with Greenockite (historic USA locale!)

Item Description

Rush is well-known for its yellow Cadmium Smithsonite after Dolomite specimens, and these were collected in old abandoned workings here by intrepid modern collectors since the 1950s. There are a few microcrystals of orange-red Greenockite along the periphery that add mineral interest to the piece, and in fact the color is due to greenockite and cadmium inclusions. What is intriguing about this specimen is that the Smithsonite appears to have grown in at least two generations. The first replaces the curved Dolomite crystals, which is classic. Looking at the specimen, there are many crystals that resemble Smithsonite scalenohedrons (think Tsumeb in style), and are the second generation of Smithsonite. Quite fascinating, and not an occurrence I have often seen from here, or anywhere. This is a quality, representative piece for this locality, but also subtly different from others. We suspect it is a very old specimen, not from modern era collecting by locals in the 80s and 90s.