Names: Calcium sulfate, Plaster of Paris, DrieriteGypsum, Calcium sulfate (anhydrous), Anhydrous calcium sulfate, Anhydrous gypsum, Anhydrous sulfate of lime, Calcium salt of sulfuric acid, CaSO4, Calcium sulphate, Calcium sulfate anhydrous, Sulfuric acid, calcium salt (1:1), [Note: Gypsum is the dihydrate form and Plaster of Paris is the hemihydrate form.]
Appearance: White solid ; White hygroscopic powder or crystalline powder ; Odorless, white powder or colorless, crystalline solid. [Note: May have blue, gray, or reddish tinge.]
H2O – Water, oxidane
Other names: Water (H2O), Hydrogen hydroxide (HH or HOH), Hydrogen oxideDihydrogen monoxide (DHMO) (systematic name), Hydrogen monoxide, Dihydrogen oxide, Hydric acid, Hydrohydroxic acid, Hydroxic acid, Hydrol, Μ-oxido dihydrogen, Κ1-hydroxyl hydrogen(0)
Appearance: White crystalline solid, almost colorless liquid with a hint of blue, colorless gas
Products:
CaSO4*2H2O
Names: Gypsum, Gypsum (mineral), Gypsum mineralCalcium(II) sulfate dihydrate, Gypsum stone, Hydrated calcium sulfate, Mineral white, Gypsum Fibrosum, Calcium sulfate dihydrate, [Note: Gypsum is the dihydrate form of calcium sulfate; Plaster of Paris is the hemihydrate form.]
Appearance: White crystalline powder or lumps ; White or nearly white, odorless, crystalline solid.
, Plaster of Paris 
; Odorless, white powder or colorless, crystalline solid. [Note: May have blue, gray, or reddish tinge.]