Test: Minerals And Rocks - UPSC MCQ

Russia accounts for approx. 21% of global diamond production, most of which is mined in the largest diamond mine Sakha Respublikata in Yakut (Yakutia) of Siberia.

Igneous rocks are formed from the solidification of magma, which is a hot (600 deg.C - 1300 deg.C, or 1100 deg. - 2400 deg. F) molten or partially molten rock material. The Earth is composed predominantly of a large mass of igneous rock with a very thin covering of sedimentary rock.

Igneous rocks form 95% of the upper part of the earth’s crust. Igneous rock is formed by the solidification of lava that comes out generally from volcanoes. Some examples of igneous rocks are: granite and basalt.

Silicate minerals are the most abundant mineral group in the Earth's crust, making up over 90% of it. Silicates are formed from groups of silicates and form rocks. Silicon is the second most abundant element in the Earth's crust, and it links up with oxygen to form the most common minerals on Earth. 

Petrology is the study of rocks - igneous, metamorphic, and sedimentary - and the processes that form and transform them. Mineralogy is the study of the chemistry, crystal structure and physical properties of the mineral constituents of rocks.

Metamorphic rocks started out as some other type of rock, but have been substantially changed from their original igneous, sedimentary, or earlier metamorphic form. Metamorphic rocks form when rocks are subjected to high heat, high pressure, hot mineral-rich fluids or, more commonly, some combination of these factors.

Lithification: This is the process where sediments are compacted and cemented together to form solid rock. It includes the processes of compaction (due to pressure from overlying sediments) and cementation (where minerals precipitate from pore fluids and bind the sediment grains together).

Coal is used as a fossil fuel and is a non-metallic mineral with dull and non-reflective properties and it cannot be moulded in any form.

The igneous rocks (Ignis – in Latin means ‘Fire’) are formed when magma cools and solidifies. As igneous rocks form out of magma and lava from the interior of the earth, they are known as primary rocks.

The minerals that do not contain metal contend are known as non-metallic minerals. Sulphur, phosphates and nitrates are examples of non-metallic minerals.

Iron is a ferrous metal. Iron and other metals often mix with iron to form various kinds of steel.