Schorl Tourmaline (ex Kay Robertson Collection)

Item Description

A showy and aesthetic display specimen of black Schorl Tourmaline from Sonora, Mexico. The label mentions that it is from a place called Santa Anna, but I can't find a listing for this actual locality anywhere, though it could be mistaken for Santa Cruz. With that said, the piece features a different style of crystals than I can remember seeing from anywhere else in Sonora, as there are multiple semi-acicular "spray"-like groups of thin prismatic crystals sitting among micro Quartz on matrix. I looked at the piece under the microscope, and some of the very thin Tourmaline crystals show a slight golden-brown hue when strongly backlit. There is also a slightly greenish-gray hue that can be seen, but I can't tell if it's coming from the Quartz or perhaps from another mineral. The longest Tourmaline group measures 2.3 cm. Ex Kay Robertson Collection (#10302). Kay was 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).