Fluorite

A most unusually crystallised thin film of purple Fluorite covers an angular shard of Carboniferous limestone from Winnats Pass, close to the village of Castleton in Derbyshire, England.  The Fluorite covers most of the flat surface of the limestone, forming concentric squares of alternating coloured Fluorite which switch between light and deep purple.  A singular specimen of Fluorite from the famous Blue John area of the Peak District National Park.