The world's gemmiest cassiterite crystals have, in the past, come from Viloco. Some Chinese crystals, some very few, now match them - but these have historicaly set the standard. However, specimens of this quality are now very scarce in the mineral market. This particular specimen is a cluster of lustrous, gemmy, brownish-tan cassiterite crystals to 2.2 cm in length. The crystal on the top left-hand side is not only gemmy but it is also classically twinned. A superb old specimen with no damage to the display face except at the bottom periphery and one contacted small crystal atop. Ex. Dr. Edward David Collection.