Sankyo Kasei Co., Ltd.

This company began business more than 100 years ago in Japan, manufacturing sodium sulfide through charcoal reduction of sodium sulfate. Sulfur inorganics still make up 25% of its sales, and the company is the sole supplier of colorless, pure crystalline sodium sulfide in the world, used for manufacturing advanced optical materials; building on its inorganic sulfur chemistry background, the company expanded into organic sulfur compounds and now offers sulfur-containing and non-sulfur specialty chemicals for a wide variety of purposes.