Common Intrusive Rocks:
* Granite: A very common and well-known intrusive rock, often seen in monuments and buildings. It's typically light-colored, coarse-grained, and contains quartz, feldspar, and mica.
* Diorite: Similar to granite but contains less quartz and more plagioclase feldspar. It's often dark gray or greenish.
* Gabbro: A dark-colored, coarse-grained igneous rock composed mostly of plagioclase feldspar and pyroxene. It's denser than granite and often found in the ocean floor.
* Peridotite: A very dense, dark-colored rock found deep in the Earth's mantle. It's composed primarily of olivine and pyroxene.
* Syenite: A light-colored, coarse-grained rock that's similar to granite but lacks quartz.
* Monzonite: A rock that falls between granite and diorite in composition.
Less Common Intrusive Rocks:
* Pegmatite: A very coarse-grained intrusive rock often containing large crystals. It can contain rare and valuable minerals.
* Dolerite (Diabase): A fine-grained, dark-colored intrusive rock often found in dykes (thin, tabular intrusions).
* Kimberlite: A rare, ultramafic rock known for its association with diamonds.
* Lamprophyre: A group of dark-colored, fine-grained intrusive rocks with a distinctive "porphyritic" texture (large crystals embedded in a finer-grained matrix).
Key Features of Intrusive Rocks:
* Intrusive rocks cool and solidify beneath the Earth's surface. This slow cooling process allows for the formation of larger crystals.
* They often have a coarse-grained texture. This means the individual mineral grains are large enough to be seen with the naked eye.
* They are often found in large, irregular masses called plutons. Plutons can be massive and can be exposed at the surface over time through erosion.
Note: The specific mineral composition of an intrusive rock can vary depending on the source magma and the conditions under which it solidified.
