B. Refractory material
C. Source in special cements
D. Precious gemstones
The question was posed to me in exam.
The doubt is from Mineral Resources of India in section Economic Mineral Deposits of Engineering Geology
The explanation is: Dolomite is carbonate rock of wide occurrence in India and elsewhere and also with wide applications as a flux in metallurgy, as a refractory material and as source material in special cement.