Very fine, this classic Congo Dioptase is an undulating and sculptural small cab that is virtually all Dioptase crystals. The Dioptases themselves are gemmy and lustrous, with a rich emerald-green color and the 'fire' that is so coveted. The largest of these is about 1.2 cm long. One side of the specimen even has a partial oxide coating on many of the crystals, which add a very attractive contrast, and sharp definition, to the crystals. #187 in Kay's collection, this old-timer certainly dates back to the 1950s or before, as it was actually acquired by Kay in 1957 from a California dealer named Shale. Good quality and good aesthetics. Highly unusual, overall. Better in person. We do not see many of these old pieces!