Illite pseudomorph after Halite (ex Kay Robertson Collection)

Item Description

An unusual specimen of Illite (a variety of Muscovite) replacing cubic Halite from a deposit in the "Auburn Shale" (according to the labe). near Peru, Nebraska. The crystals measure up to 1.0 cm on edge. Strange material, I've never offered anything like it before in the aucitons. The label accompanying the piece states that the piece is a pseudomorph of "Mud" after Salt or Sylvite, but I found a few others listed online that are labeled as Illite after Halite. A really cool piece of this rare material from Nebraska. Ex Kay Robertson Collection. 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 Velt" November-December 2017).