Description
Blue John is a local name for a banded white/purple variety of Fluorite from the Castleton area of Derbyshire, England, UK. And this specimen is one of this extremely rare material. A colorful slab with banding from deep purple to several lighter shades of purple. Over centuries, collectible items such as decorator items such cups, etc. were cut. Very coveted not only by mineral collectors. The display side of the specimen, which is from the type locality (!) the Blue John Mine, is polished, the reverse is cut and unpolished.