A pleasing miniature specimen of Cassiterite pseudomorph after Orthoclase, from the classic Cornish location of Wheal Coates. The Cassiterite forms an inter grown cluster of several Carlsbad law twinned crystals. The twinned crystals show a typical matt brown granular texture. Most of these pseudomorphs came from a small stretch of a vein in the late 1820s. A real Cornish classic from Wheal Coates.