Scheelite / Stolzite on Zinnwaldite (ex Kay Robertson Collection)

Item Description

The label accompanying this specimen states that it hosts Scheelite on Zinnwaldite, but mentions that is was previously labeled as Stolzite. Since both species are reported from Cinovec / Zinnwald, it's impossible to know which species is present visually, it would require chemial analysis, as both species have similar crystal habits. Additoinally, it should be noted that the mica species, "Zinnwaldite" has been discredited, and now lies in the Siderophyllite-Polylithionite zone, but it is essentially defined as a dark mica containing lithium. A coverage of sharp, lustrous, muted tan colored tetragonal crystals of either Scheelite or Stolzite measuring up to 4 mm are coating the underlying "Zinnwaldite" mica matrix. The piece shows a fluorescence that makes me think it's probably Scheelite, but it should be analyzed to know for sure. Classic old material from this very old locality on the German / Czech border. Ex Kay Robertson Collection (#3553). 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).