"Phengite" (superb color!) (ex Brian Kosnar Collection

Item Description

At first glance, this specimen of "Phengite" (a series between Muscovite and Celadonite) is an ordinary Mica crystal, but when strongly backlit, AND viewed from the side, one can see the most intense internal blue-green color! This is a most surprising specimen considering that Mica is rarely colorful, let alone has such a vibrant hue like this piece. I'm told that "Phengite" was at one time a valid species, and the color is due to the presence of Chromium and/or Titanium cations. This is one of the few specimens of this material that I have seen, and comes from the collection of Brian Kosnar who purchased it from Carlos Barbosa at the Tucson Show in 2000. A very cool and rarely seen specimen of this unique material!