Dioptase on Plancheite / Chrysocolla (?) (ex Kay Robertson Collection)

Item Description

An attractive older specimen of the well-known Reneville Dioptases, which are some of the most well-known example of the species outside of Tsumeb extant. A group of lustrous, well-formed, sharp, trigonal, gorgeous emerald green prisms of Dioptase with no matrix, but an association of soft powder blue colored botryoidal Plancheite / Chrysocolla on the reverse side. The largest Dioptase measures 2.2 cm long, but it like several crystals on the piece is contacted, so it's not 100% damage free. Some of the crystals show good gemminess when backlit. No real damage that I can see with the naked eye. Ex Kay Robertson Collection (#12035). Kay is a prominent California collector, who specialized in European classics (see the article in the March-April, 2007 Mineralogical Record and the 50+ page article in the German Magazine "Mineralien Welt" November-December 2017).