EVERYDAY SCIENCE

Detailed explanation-1: -Porphyritic – The texture of an igneous (volcanic or plutonic) rock that contains large crystals (phenocrysts) in a fine-grained groundmass.

Detailed explanation-2: -Intrusive igneous rocks cool from magma slowly in the crust. They have large crystals. Extrusive igneous rocks cool from lava rapidly at the surface. They have small crystals.

Detailed explanation-3: -3.2: Intrusive igneous rocks form at some depth within the crust due to slow cooling of magma, resulting in formation of large crystals. Individual crystals can be seen with the naked eye. These rocks are termed texturally as coarsely crystalline or phaneritic.

Detailed explanation-4: -The size of crystals in an igneous rock is an important indicator of the conditions where the rock formed. An igneous rock with large crystals probably indicates that the rock formed deep within the Earth, since it is typically warmer deep inside the Earth than near the surface.

Detailed explanation-5: -When magma and lava cool and harden, they create igneous rocks. These rocks may be extrusive or intrusive, depending on where the magma or lava crystallizes. Basalt is the most common extrusive rock while granite is a very common intrusive rock.