Jarosite with Copiapite and Natrojarosite (ex Kay Robertson Collection)

Item Description

A cool association specimen from what mindat.org calls the "most important mine of the Calamita peninsula". This piece features a coverage of dozens of gemmy, sparkling, rich honey-golden colored crystals of the potassium iron hydroxy sulfate Jarosite which are associated with minor yellow crystals of the hydrated iron hydroxy sulfate Copiapite sitting atop a matrix of chocolate brown Natrojarosite (a sodium iron hydroxy sulfate). The piece is best viewed with a loupe or more preferably under the microscope, but we have photographed the piece with a Canon MP-E 65 mm macro lens to better illustrate the quality. A great combination / association specimen from this famous old mine dating back to the 1800s. Ex Kay Robertson Collection (#8612). 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).