An excellent specimen of Cassiterite from a mine that is well regarded for giving up well-formed crystals of the species, namely the Old Beam Mine in the heart of the China Clay district, Cornwall, England. Lustrous deep brown/black crystals of Cassiterite measuring to 1.1cm are seen as clusters and singles. Intergrown with translucent prismatic Quartz crystals and groups of lustrous black Tourmaline needles.