Source special issue: classic-minerals-of-northern-england, PDF page: 81. Label: Zoned fluorite crystal, 6 cm, from the Boltsburn mine, Rookhope, Weardale, Durham; this is a pre-1840 specimen (LG-403) acquired by the British Museum (Natural History) in 1862. It was traded by the Museum to Anthony Walshaw in the 1980s, who sold it to Lindsay Greenbank in 1989. Joe Budd photo.

Origin: Boltsburn mine, Rookhope, Weardale, Durham