66. Which mineral is commonly used in the production of semiconductors?
a) Quartz
b) Feldspar
c) Diamond
d) Graphite
Answer: a) Quartz
67. Which mineral is the primary source of silver?
a) Hematite
b) Galena
c) Calcite
d) Halite
Answer: b) Galena
68. Which mineral is used in the production of soaps and detergents?
a) Gypsum
b) Halite
c) Calcite
d) Pyrite
Answer: b) Halite
69. Which mineral is commonly used in the production of cemented carbides?
a) Quartz
b) Diamond
c) Tungsten carbide
d) Feldspar
Answer: c) Tungsten carbide
70. Which mineral is commonly used as a gemstone?
a) Apatite
b) Quartz
c) Pyrite
d) Barite
Answer: b) Quartz
