Fluorite - Blackdene Mine, Weardale, GB
 
The bluish-green Fluorites have intensely sharply zoned edges (phantom). The front surface of the Fluorites is encrusted with Quartz. Two highly lustrous yellow chalcopyrites sit centrally on the quartz. At one tip of the upper fluorite is a 3mm long damage barely visible to the naked eye.
Around the present Blackdene Mine, mining was carried out as early as the 15th century. The mine was worked by several companies during the 20th century until 1987 when it was finally closed down. The mine is still accessible, but large parts of it are under water. Thus, minerals from this site are very rare and sought after.