Fluorite and siderite, Boltsburn Mine, Rookhope

A group of grey/light brown fluorite crystals together with dark brown siderite crystals, from Boltsburn Mine, Rookhope, Weardale. This specimen appears to be a floater as no attachment point can be seen. Collected by Sir Arthur Russell and donated to the British Museum (Natural History) in 1955 and later released by them.