Ig-morph-mentary

There are three main types of rocks that we have been discussing in class--igneous, metamorphic, and sedimentary. Igneous rocks are formed through the cooling and sedimentation of lava. Metamorphic rocks are characterized by the fact that they are the product of a transformation of an existing rock type. And a sedimentary rock is a type of rock that is formed by sedimentation of material at the Earth's surface and within bodies of water.

Examples of Igneous Rocks:

This is basalt, which is an extrusive volcanic rock that just so happens to be the most common rock found in the Earth's crust.

Granite is a type of intrusive, felsic, igneous rock that are found on many kitchen countertops around the world, including mine. 

Examples of Metamorphic Rocks:

"You better watch out. You better not cry. You better not pout, I'm telling you why: Santa Claus is coming to town!" This is anthracite coal, commonly found in the stockings of bad boys and girls around the globe. It is a combustible rock normally occurring in rock strata in layers. It is considered a metamorphic rock, because of exposure to elevated temperature and pressure.

Well isn't this a "gneiss" rock. This is gneiss--a type of rock that is formed by high-grade metamorphic processes from pre-existing formations.

Examples of Sedimentary Rocks:

Ooooooooh pretty! Yeah, yeah, yeah...this rock has heard that before. This is a sedimentary rock by the name of "Obsidian". It is defined as "a naturally occurring volcanic glass." It is composed of high iron and nickel content.

This is limestone--a sedimentary rock composed of crystalized forms of calcium carbonate. Limestone can be found on many buildings, for example, Hardeman Hall--the Fine Arts building--right here on Mercer's wonderful and beautiful campus.