igneous rocks..

igneous rocks.....

Basalt: Basalt is a dark-colored, fine-grained, igneous rock composed mainly of plagioclase and pyroxene minerals.
granite:Granite is a light-colored igneous rock with grains large enough to be visible with the unaided eye.
Obsidian: Obsidian is a dark natural glass that forms when lava cools.
Pegmatite: Pegmatite is a very extreme igneous rock with lots of crystals.