Cassiterite var. Wood Tin with Quartz and Dolomite

A good example of the variety of Cassiterite known as Wood Tin, due to its concentric banded appearance. This specimen is known to originate from Cornwall, but its exact locality is not recorded. Near-horizontal bands of sooty-black-grey Cassiterite are interbedded with milky-white massive Quartz forming a layer-cake structure and showing the Wood Tin to good effect. One face has been polished to enhance the structural detail. The top surface is totally covered with an attractive layer of up-standing Quartz crystals heavily coated with micro-crystals of Dolomite and probable Siderite.