Cassiterite

Instantly, on lifting this specimen from Wheal Pendarves, it is apparent a good proportion is Cassiterite because of its unexpected high weight.  Much of the specimen on one side is milky vein Quartz and this obscures the high Cassiterite content.  Seen from the opposite side, which would probably be considered the base, more massive Cassiterite is visible.  In the many vugs where Cassiterite crystals have developed, the crystal habit tends to be elongated, forming sparable crystals.  Sparable tin was the miner’s term for acicular habits of Cassiterite, named for their similarity to a ‘sparrow’s bill’ or the name for hand-made nails used in the mines.  The accompanying British collector’s label records it was collected in August 1975 from the Tryphena Lode; a lode known for its instability and high permeability where the workings were always very wet.  Wheal Pendarves is by the village of Killivose, a little south of Camborne in Cornwall, England.