Gypsum company list in Iran. Gypsum company list, 44, in Iran, include Tehran,ISFAHAN,Esfahan,Mashhad,Tabriz,Iran . Semnan Accounts for 6% of World Gypsum Production, Semnan Accounts for 6% of World Gypsum Production, Although there are underground gypsum mines in many countries around the world, almost all the gypsum in Iran .