Optical "Iceland spar" Calcite (Kay Robertson Coll.)

Item Description

A striking and fine specimen of water-clear "Iceland spar," or calcite showing the classic double refractivity which we all learned about in high school science class from a small sample of this stuff. This is actually a very good polished example of the material from Mexico, for reference or education. Note this is of course cleaved (perfectly) on all sides, along the natural cleavage planes of calcite, from a massive rough specimen. Ex Kay Robertson Collection # 8870 and acquired from the Cisneros' at the 1979 MSSC Show. Kay is a prominent California collector, who specialized in European classics (see the article in the March-April, 2007 Mineralogical Record).