These elbaite tourmaline crystals are from Cruziero in Sao Jose da Safira, Minas Gerais, Brazil. Almost Twenty different minerals are found at the mine including elbaite. Elbaite is in the Tourmaline Group of minerals. It is a silicate and it contains the elements Al, B, H, Li, Na, O and Si. It can be found in a variety of colors which are caused by traces of other elements in the crystal lattice. These crystals are green with brownish terminations. They are transparent with a glass luster. They form a complex termination that has a hollow appearance. The hollow hosts secondary tourmaline and cleavelandite crystals. This piece measures approximately 1 5/8 x 5/16 x 3/16 inches or 42 x 8 x 5 mm. It weighs 2.18 grams.