Fluorite with galena and baryte, from Crich, Derbyshire, England
Geological description:
Hydrothermal vein deposit of colourless to yellow iron-stained fluorite with galena and white crested baryte. Fluorite zoned with inclusions of marcasite/pyrite.
Comments:
This specimen was given to Corsi by the 6th Duke of Devonshire following the Duke's visit to see Corsi's collection in 1824. It is not Blue John, the variety that was usually used for decorative purposes. Note that Derbyshire fluorite, of which this is a typical example, is not normally fluorescent under ultraviolet radiation.