Bacterial alteration of anhydrite or gypsum, in the presence of hydrocarbons, produces limestone and hydrogen sulfide in the sulfur cycle.

The hydrogen sulfide then oxidizes into sulfur, from percolating water, or through the action of anaerobic, sulfur-reducing bacteria [3][4] In 1867, miners discovered sulfur in the caprock of a salt dome in Calcasieu Parish, Louisiana, but it was beneath quicksand, which prevented mining.

[3] When Frasch's patent expired, the process was widely applied to similar salt-dome sulfur deposits along the Gulf Coast of the United States.

The Gulf Coast came to dominate world sulfur production in the early and middle 20th century.

The Frasch process is still used to work sulfur deposits in Mexico, Ukraine and Poland.

3-38 cubic meters of superheated water are required to produce every tonne of sulfur, and the associated energy cost is significant.