Wheal Coates, St. Agnes, Cornwall.
An unusual specimen which displays feldspar crystals in elvan matrix that have been replaced by cassiterite, the largest of these is 1.5 cm long.
The slab has been polished on one side and is Interesting in that it shows the boundary of cassiterite enrichment which runs through the centre of the specimen.
Size 15 x 10 x 1 cm