K-Feldspar (var: Adularia) (twin) with "Chlorite" (ex Geary Murdock Collection)

Item Description

A classic example of the famous Adularia twins from the renowned Val Cristallina (Crystal Valley) in Switzerland. This piece is a sharp, large, thick, well-formed, beautifully twinned crystal group that I would classify as being a "near floater" as it's crystallized nearly all the way around, but there are a few tiny contacts that keep it from being 100% pristine. For years, Adularia was defined as a variety of Orthoclase, but now it's defined as a variety of either Orthoclase or Microcline depending upon the habit (monoclinic or triclinic). The rich moss-green color is due to a coating of Chlorite, which has created nearly full-on green Adularia crystals - with only a tiny bit of white showing here and there. This is a fairly large twinned Adularia from any locality, and the fact that it's Swiss makes it all the more valuable in terms of Alpine material. Valued at $950. From the worldwide collection of noted Idaho collector Geary Murdock. Among other accomplishments, Geary was responsible for discovering some of the finest gem grade deep blue Aquamarine crystals in the Sawtooth Mountains of Idaho - which remain arguably the finest Aquamarines from any North American locality. https://www.findagrave.com/memorial/36634006/geary-jack-murdock