Cassiterite and Cosalite, with Quartz
Miniature, 4.8 x 4.4 x 4.3 cm
Amo Sn deposit, Ximeng Co., Pu'er Prefecture, Yunnan, China

As I stare at this large miniature, I find the incredible gemminess of these Cassiterites so remarkable and mesmerizing that I am simply drawn in like a moth to the flame. These tetragonal crystals are surprisingly transparent, and vary in color from shades of coffee-brown to golden-amber. The luster on these Cassiterite crystals is perfectly glassy, and the sharp and abundant twinning is outstanding. The crystals average over 2.5 cm in size, and they have a superb, cross-hatched, 2.5 cm cluster of metallic Cosalite associated with it. VERY rare! Choice in every way, the gemmy Cassiterites in this large miniature are not to be confused with the far more common, and opaque, black Cassiterites from Pingwu. This small and remote deposit has produced the gemmiest Cassiterites from China, and the best since the Bolivian material of the 1970s came out. The photos do a good job showing just how good this piece is, but in reality it is even better in person. Among the finest in size class and among the finest of this style form china, period, circa 2010.