Calcite on "Turgite" (ex Kay Robertson Collection)

Item Description

A strange and obviously rare specimen from this lesser known locality in the Siegerland of North Rhine-Westphalia, Germany. Small rhombic white crystals of Calcite forming semi-"rosettes" are sprinkled all over beautifully iridescent (blue-green, yellow, orange, pink, blue and purple) "Turgite" matrix. According to mindat.org Turgite is "Often referred to as a "variety" of either hematite or goethite, it is a mixture of the two minerals due to the alteration of goethite, typically found in the botryoidal habit of the "parent" goethite". It is not a valid species, but the term is still used widely today to refer to any iridescent uncrystallized iron oxide like this. Ex Kay Robertson Collection (#2554). 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). A great piece to add to a German mineral collection, as I've never seen one before and they are certainly rare.