Rocks

Courtney Morris
science 7-2
november 19, 2014

Igneous

Pegmatiteis a light-colored, extremely coarse-grained intrusive igneous rock. It forms near the margins of a magma chamber during the final phases of magma chamber crystallization. It often contains rare minerals that are not found in other parts of the magma chamber. The specimen shown above is about two inches (five centimeters) across.

Metamorphic

Marble is a non-foliated metamorphic rock that is produced from the metamorphism of limestone. It is composed primarily of calcium carbonate. The specimen shown above is about two inches (five centimeters) across.

Sedimentary

Coal is an organic sedimentary rock that forms mainly from plant debris. The plant debris usually accumulates in a swamp environment. Coal is combustible and is often mined for use as a fuel. The specimen shown above is about two inches (five centimeters) across.