Baryte

Baryte, or Barytes, is the natural sulphate of barium, a common mineral, occurring commonly as a veinstone with metallic ores. It crystallises, often in large crystals, belonging to the prismatic system, and also occurs in stalactitic and other massive forms. It is colourless, white or yellow brown, so that the stalactites resemble fossil wood, but are recognisable by their weight. Its specific gravity is about 4.5, whence it was formerly confused with witherite, celestite and strontianite, under the name "heavy spar." It is translucent and vitreous, and has a white streak. It fuses with difficulty, decrepitating and colouring the flame yellowish-green. With sodium carbonate it sinks into charcoal or will stain silver black. The mineral is ground up and mixed with white lead as a paint.