Natural gypsum is the most common form of gypsum
used around the world and but consumption of synthetic
material has started to rise sharply, especially in Europe
and North America. The most source of synthetic gypsum
is produced by flue gas desulphurisation (FGD)
equipment at coal-fired power stations. Global consumption
of gypsum in all its forms was estimated at
149 Mt in 2003 (Wood, 2005).