This is an oxidation-reduction (redox) reaction:
SVI + 8 e- → S-II (reduction)
4 C0 - 8 e- → 4 CII (oxidation)
CaSO4 is an oxidizing agent, C is a reducing agent.
Reactants:
, Plaster of Paris
, Anhydrous calcium sulfate
, Anhydrous gypsum
, Anhydrous sulfate of lime
, Calcium salt of sulfuric acid
, CaSO4
, [Note: Gypsum is the dihydrate form and Plaster of Paris is the hemihydrate form.] 
; Odorless, white powder or colorless, crystalline solid. [Note: May have blue, gray, or reddish tinge.] 
Products:


, Monoxide
, Carboneum oxygenisatum 
, Carbonic oxide 
; Colorless, odorless gas. [Note: Shipped as a nonliquefied or liquefied compressed gas.] 