Cassiterite

The St. Agnes granite is a small offshoot of the Carnmenellis pluton and contained two major veins rich in tin mineralisation.  This large miniature is densely coated with reasonably well-formed Cassiterite crystals of typically 2 to 4 mm across, of dark chocolate brown and where translucent, bright orangey-clove brown.  Typical of the Cassiterite veins at St. Agnes, small milky Quartz crystals underlie and meander amongst the Cassiterite crystals, providing a nice degree of contrast.  A nice example of crystallised Cassiterite from St. Agnes, on the coast to the north of Redruth in Cornwall.