These dravite tourmaline crystals are from the Powers Farm in Pierrepont, St. Lawrence County, New York, USA. This locale contains dozens of minerals but is most famous for the lustrous black dravite that have been found there. It is a silicate in the tourmaline series of minerals. It contains a variety of elements that include; Na, (Mg) al Si, O, B and H. This piece consists of a quartz and dravite matrix that is topped with quartz crystals and bright black dravite crystals. This piece measures 3 x 2 x 1 1/8 inches or 76 x 52 x 28 mm.