Minor mineral deposits in Sikkim include:

Graphite
Dolomite
Quartzite
All of the above

The correct answer is: d) All of the above.

Graphite, dolomite, and quartzite are all minor mineral deposits found in Sikkim. Graphite is a mineral that is used in the production of steel, batteries, and lubricants. Dolomite is a mineral that is used in the production of cement, glass, and ceramics. Quartzite is a mineral that is used in the production of building materials, abrasives, and filters.

Graphite is a soft, black mineral that is composed of carbon atoms arranged in a hexagonal lattice. It is the most stable form of carbon and is found in nature as a solid. Graphite is a good conductor of electricity and heat, and it is used in a variety of applications, including the production of steel, batteries, and lubricants.

Dolomite is a mineral that is composed of calcium magnesium carbonate. It is a white or gray mineral that is found in nature as a rock. Dolomite is used in the production of cement, glass, and ceramics. It is also used as a flux in the iron and steel industry.

Quartzite is a mineral that is composed of quartz. It is a hard, white or gray mineral that is found in nature as a rock. Quartzite is used in the production of building materials, abrasives, and filters. It is also used as a filler in rubber and plastics.