Quartz var. Chalcedony on Fluorite

The combination of simply fascinating structural forms and colours of Chalcedony and from one of Redruth’s most famous mines makes this a wonderful specimen from a rarely seen locality.  The Pednandrea mine was already working in the early 1700’s and finally closed in 1891.  It was situated in what is now almost central Redruth, a little north east of the present railway station.  This rich tin mine became famous for its fine Chalcedony, a microcrystalline variety of Quartz and is also known amongst collectors for Fluorite.  Given the extensive and complex mineralogy of Cornwall, Fluorite is fairly scarce.  Part of the matrix of this specimen is massive, cryptocrystalline green Fluorite, an interesting feature in itself.  Totally covering the large, 12.5 x 16.6 cm display surface, the Chalcedony forms a bubbly, undulating bed of bluish-grey, butter-milk and buff spherules, many becoming elongated to small stalagmitic habits.  Over this layer are many long, snake-like sinusoidal structures of clotted-cream coloured Chalcedony, up to almost 5 cm long and adding a delightful three dimension layer.  A great and extremely rare specimen of Chalcedony on Fluorite from the old Pednandrea mine in Redruth, Cornwall.