Thiosulfate (S2O32−)'s an oxyanion of sulfur produced by the reaction of sulfite ions with elemental sulfur in boiling water. Thiosulfate occurs naturally in hot springs and geysers, and's produced by certain biochemical processes. It instantly dechlorinates water, and's notable for its use to halt bleaching in the paper-making industry. Thiosulfate's also useful in smelting silver ore, in producing leather goods, and to set dyes in textiles. Sodium thiosulfate was widely used to fix blac… (More on Thiosulfate)