Quartzite, found in Sikkim, has applications in:

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

Quartzite is a hard, dense, and durable metamorphic rock composed of quartz. It is found in a variety of colors, including white, gray, pink, red, and brown. Quartzite is used in a variety of applications, including:

• Glass manufacturing: Quartzite is used as a raw material in the manufacture of glass. It is also used as a flux, which is a substance that lowers the melting point of other materials.
• Ceramics: Quartzite is used in the manufacture of ceramics, such as pottery and porcelain. It is also used as a filler in concrete and other building materials.
• Electronics: Quartzite is used in the manufacture of electronic components, such as capacitors and resistors. It is also used as a piezoelectric material, which is a material that can generate an electric charge when it is subjected to mechanical stress.

Quartzite is a valuable resource that has a wide range of applications. It is found in many parts of the world, including Sikkim.