important large Smithsonite ps. Dolomite on Quartz ex Halpern

Item Description

Of all Jack Halpern's many dozens of smithsonites in the collection, this was the only large USA-origin smithsonite specimen: It is from the unique occurrence in central Arkansas where the presence of both cadmium and of the cadmian-rich species greenockite causes these saddle-shaped crystals to have a vibrant yellow color. This large plate is in amazing condition, pristine, with dozens of sharp crystals to 1 cm. The smithsonite is actually a pseudomorph after earlier dolomite crystals, hence the unusual shape of the crystals. This is classic for the locality and I bleieve fairly unique in the world, as well. The plate is of unusual size, but moreoever has a sparkle to it that you only see on 1 in 100 specimens from this location, of tiny druse of quartz microcrystals sprinkled on the silicified (hard, quartz-infused) limestone matrix. In a case, this is incredibly dramatic! It looks like a yellow boomerang from a distance. It is one of only a handful of large, cabinet sized examples from this location of which we are aware, in quality. Halpern #3723, although earlier provenance is lacking. In person, this is shocking for the size and richness of smithsonite in contrast of the sparkly matrix. Difficult to value, as we have never seen a comparable one for sale in this size.