Calcium carbide, CaC2 when pure, is transparent and colorless, with a specific gravity of 2.22 at 180oC. Commercial calcium carbide is the main source of acetylene, and acetylene is used principally in the synthesis of a series of organic chemicals, resins, and plastics and in oxyacetylene welding and cutting of metals. The main raw materials required for the manufacture of the product are limestone containing at least 98 per cent of calcium carbide, charcoal and petroleum coke.