This tourmaline is from the Chia Mine, Sao Jose da Safira, Doce Valley, Minas Gerais, Brazil. They are elbaite crystals that are part of the Tourmaline Group of minerals. They contain the elements Al, B, H, Li, Na, O, and Si. The presence of trace elements in the lattice of the crystal are responsible for producing a variety of colors. These 3 blue-green elbaite crystals have a matrix of lavender lepidolite and beige mica crystals. The primary (central) crystal is about 20 mm long. This piece measures 5 3/4 x 3 1/8 x 2 1/2 inches or 146 x 79 x 64 mm mm.