Volborthite (classic material) (ex Kay Robertson Collection)

Item Description

A classic specimen of the famous Volborthites from Monument Valley, Arizona. This piece features beautiful electric yellow-green colored "rosettes" of Volborthite sprinkled on the schist matrix. Specimens of this sought after copper vanadate are seldom seen on the market, and are desirable among Arizona collectors and micro collectors alike for their beauty. The label mentions that the blue mineral on the piece is Allophane, but it's not reported from the locality, so I'm not entirely certain what it is. Ex Kay Robertson Collection (#4209) with a label from John L. Parnau of Campbell, California. 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).