Quartz / Chalcedony "cast" after Calcite (ex Kay Robertson Collection)

Item Description

A rarely seen example of silvery-brown colored Quartz / Chalcedony which has formed hollow "casts" (perimorphs) after preexisting scalenohedral crystals of Calcite. The Calcites have been completely dissolved away, leaving their original crystal form now preserved by the translucent Quartz / Chalcedony. The largest crystal cast measures 2.0 cm. A really cool piece for anybody who collects California minerals or replacement / "casts" specimens. Ex Kay Robertson Collection (#440). 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).