Black Tourmaline forms in granite pegmatites and metamorphic rocks, This iron-rich variety of tourmaline, known mineralogically as schorl, crystallises in the trigonal system and typically occurs as elongated prismatic crystals with characteristic vertical striations along their length.
Black Tourmaline develops during the late-stage crystallisation of granitic melts, where boron-rich fluids facilitate its growth. The crystals often form in association with quartz, feldspar, and mica, and can range from small millimetre-sized specimens to impressive crystals exceeding 30 centimetres in length. The deep black coloration results from high iron content in the crystal structure, though some specimens may show a subtle blue or brownish tint when examined with bright light.
