Igneous Rocks With Large Crystals

Igneous rocks that are formed underground are called intrusive igneous rocks.
Igneous rocks with large crystals. The large grains are called phenocrysts and rock with phenocrysts is called a porphyry that is it has a porphyritic texture. There are two basic types. Igneous rocks contain randomly arranged interlocking crystals. What are igneous rocks.
They are characterized by large crystals mostly visible with the naked eye. Igneous rocks are formed from the solidification of molten rock material. Intrusive igneous rocks are formed when the magma cools off slowly under the earth s crust and hardens into rocks. Types of igneous rocks.
The size of the crystals depends on how quickly the molten magma solidified. Rapid cooling results in smaller crystals while slow cooling results in large crystals. Examples of intrusive igneous rocks are diabase diorite gabbro granite pegmatite and peridotite. In many igneous rocks large mineral crystals float in a fine grained groundmass.
Igneous rocks are of two types intrusive plutonic rocks and extrusive volcanic rocks. Magma that cools slowly will form an igneous rock with.