154 carats of graduated natural Herkimer Diamonds. World famous Herkimer Diamonds are beautifully doubly-terminated quartz crystals already faceted by nature. The bedrock in which the crystals are found began forming approximately half a billion years ago in a shallow Cambrian sea that lapped against the southern shores of the ancestral Adirondack Mountains. I prefer to use the pieces just as they come from the ground. Extremely rare, and imperfectly beautiful! This piece has visible tourmaline mixed into the clear gems- stunning! 15 1/2 inches plus a 3 inch extender.