1. . 
A dense sulfate mineral that can occur in a variety of rocks, including limestone and sandstone, with a range of accessory minerals, such as quartz, chert, dolomite, calcite, siderite and metal sulfides. Barite is commonly used to add weight to drilling fluid. Barite is of significance to petrophysicists because excess barite can require a correction factor in some well log measurements.
Alternate Form: baryte
2. . 
A dense mineral comprising barium sulfate [BaSO4]. Commonly used as a weighting agent for all types of drilling fluids, barites are mined in many areas worldwide and shipped as ore to grinding plants in strategic locations, where API specifies grinding to a particle size of 3 to74 microns. Pure barium sulfate has a specific gravity of 4.50 g/cm3, but drilling-grade barite is expected to have a specific gravity of at least 4.20 g/cm3 to meet API specifications. Contaminants in barite, such as cement, siderite, pyrrhotite, gypsum, and anhydrite, can cause problems in certain mud systems and should be evaluated in any quality assurance program for drilling mud additives.
See: abrasion test, attapulgite, caustic extraction test, conventional mud, greasing out, gunning the pits, heavy metal, high-gravity solids, jar test, kill-weight fluid, pilot test, settling pit, slug, unweighted mud, water, oil, and solids test, weighted mud, weighting material