How are diamonds formed? are they formed the same way as igneous rocks?

Igneous rock are formed by the cooling and crystallization of molten rock and are formed by the cooling of magma above earth's surface.

Let's look into the statements one by one:

Igneous rocks are formed only from material ejected during a volcanic eruption.

-This is not true because igneous rock can also be formed by the cooling down of magma inside a volcano or magma that was trapped in the crack of crust.

Igneous rocks are formed by the cooling and crystallization of molten rock.

-This is correct.

Igneous rocks are produced by the weathering and transport of pre-existing rocks.

-This is incorrect as igneous rock is formed by volcanism. The rock that are formed with the statement is sedimentary rock.

Igneous rocks are formed by the cooling of magma above earth's surface and lava below the surface.

-This is correct. Both intrusive and extrusive volcanic activity forms igneous rock after cooling down.

Igneous rocks are formed by recrystallization

-This is not true as recrystallization does not take place in the formation of the igneous rock. The rock formed by recrytillization is metamorphic rock.

Therefore,the igneous rock are formed by the cooling and crystallization of molten rock and are formed by the cooling of magma above earth's surface.

Hope it helps!