Cassiterite with Wolframite

Black granular Cassiterite and lustrous black blades of Wolframite richly cover and pervade a block of remnant etched Quartz from the weathering of granite within the Goonbarrow China Clay Pit at Bugle, near to St. Austell in Cornwall.  The Wolframite blades measure up to 3 cm tall and all mineralised surfaces have a partial coating of mm-sized Tourmaline crystals.  Wolframite is the intermediate member of the Hübnerite and Ferberite series.  This specimen was collected in September 1995 by Maurice Grigg and his accompanying label reads “from the old Imperial Mine in the Goonbarrow Complex. Old Beam North, Imperial N.E.”.