Barite (BaSO4) is a mineral consisting of barium sulfate. It is generally white or colorless, and is the main source of barium. Baryte is the British spelling.
Barite commonly occurs in lead-zinc veins in limestones, in hot spring deposits, and with hematite ore. It is often associated with the minerals anglesite and celestite.
The name barite is derived from the Greek word barus (heavy). In commerce, the mineral is sometimes referred to as "barytes." The term "primary barite" refers to the first marketable product, which includes crude barite (run of mine) and the products of simple beneficiation methods, such as washing, jigging, heavy media separation, tabling, flotation, and magnetic separation. Most crude barite requires some upgrading to minimum purity or density. Barite that is used as an aggregate in a "heavy" cement is crushed and screened to a uniform size. Most barite is ground to a small, uniform size before it is used as a filler or extender, an addition to industrial products, or a weighting agent in petroleum well drilling mud specification barite.
Barite has also been used in the manufacture of paints and paper. Although barite contains a "heavy" metal (barium), it is not considered to be a toxic chemical by most governments because of its extreme insolubility.
Mohs hardness is 3. Refractive index is 1.63. Specific gravity is 4.3-5. Crystal structure is orthorhombic.