Acanthite (old classic) (ex Kay Robertson Collection)

Item Description

An attractive thumbnail specimen featuring sharp, lustrous, silvery colored well-formed Acanthite crystals on matrix. The crystals measure up to 1.1 cm and show the classic pseudo-cubic habit (they're actually monoclinic). Please note, these are not pseudomorphs after Argentite as often labeled because Argentite cannot exist at our current atmospheric pressure below 177C, so all of these silver sulfide specimens are Acanthite. Very attractive overall and a fine representation of this historic material. Valued at $750. Ex Kay Robertson Collection (#3050). 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). A great German classic from the famous locality.