Molybdenum Trioxide occurs as an odorless powder, or in granular or crystalline form.
Molybdenum Trioxide is white, or slightly yellow to slightly bluish, depending on the temperatures. Molybdenum Trioxide readily combines with acids and bases to form a series of polymeric compounds.

Molybdenum disulfide is the inorganic compound with the formula MoS2. This black crystalline sulfide of molybdenum occurs as the mineral molybdenite. It is the principal ore from which molybdenum metal is extracted. The natural amorphous form is known as the rarer mineral jordisite. MoS2 is less reactive than other transition metal chalcogenides, being unaffected by dilute acids. In its appearance and feel, molybdenum disulfide is similar to graphite. Indeed, like graphite, it is widely used as a solid lubricant because of its low friction properties, sometimes to relatively high temperatures.

Phosphomolybdic acid, also known as dodeca molybdophosphoric acid or PMA is a component of Masson's trichrome stain. It is a yellow-green compound, freely soluble in water and polar organic solvents such as ethanol. It is used as a reagent in thin layer chromatography for staining phenolics, hydrocarbon waxes, alkaloids and steroids.