Rock Classification
| IGNEOUS | Rocks that have solidified from a
molten state. There are two types of Igneous rocks:
Plutonic - Rock from magma rising up from deep under the earth's crust; solidified before it reached the earth's surface. Volcanic - Rock that was originally lava, hot magma that reached the surface of the earth before it hardened. |
plutonic igneous rocks - Granite,
Peridotite volcanic igneous rocks - Obsidian, Basalt, Rhyolite |
| SEDIMENTARY | Rock formed by the accumulation of particles on or near the earth's surface, and compacted down, often under pressure, creating rock layers. | Limestone, Shale, Sandstone, Dolomite, Gypsum, Quartzite, and stones containing fossils |
| METAMORPHIC | Rocks resulting from changes within preexisting rocks, by extreme pressure, temperature, and chemical activity. | Kyanite, Mica, Garnet, Calcite, Quartz, Pyrite, Marble, Gneiss, Schist |