Cassiterite

A compact miniature which aptly demonstrates key mineralisation at the iconic landmark of St. Michael's Mount in Mount's Bay, Marazion, Cornwall.  The top surface of a light grey greisen vein is coated with buff-tan blades of Zinnwaldite mica and amongst this sit four well developed black Cassiterite crystals up to 0.9 cm.  When back lit by strong light, the edges of the Cassiterite crystals are translucent dark clove-brown.  Although tiny, a 5 x 1 mm rib of pale bluish-green Topaz is also present amongst the Zinnwaldite.  A small specimen that packs plenty of punch!