Large Calcite "Iceland spar" cleavage

Item Description

An impresssive large, blocky rhombohedral cleavage of "Iceland spar" calcite from an unnamed Coahuila locale. The transparent, lustrous calcite has satin lustre faces. Iceland spars is an optically clear form of calcite, originally from Iceland, but can occur anywhere. Classic, typical double refraction is not visible on this piece, due to the satin lustre of the faces. Interestingly, this piece does not fluoresce, as some examples do. Older material from an East Coast collection.