The correct answer is (a) Magnesite.
Magnesite is a magnesium carbonate mineral. It is a white, gray, or brown mineral that is found in metamorphic and igneous rocks. Magnesite is used in a variety of industries, including the chemical, metallurgical, and refractory industries.
Graphite is a carbon mineral that is used in a variety of applications, including pencils, lubricants, and electrodes. Graphite is a soft, black mineral that is found in metamorphic and igneous rocks.
Gypsum is a calcium sulfate mineral that is used in a variety of applications, including drywall, plaster, and fertilizer. Gypsum is a white, yellow, or brown mineral that is found in sedimentary rocks.
Dolomite is a calcium magnesium carbonate mineral that is used in a variety of applications, including cement, glass, and ceramics. Dolomite is a white, pink, or brown mineral that is found in sedimentary rocks.