This Flash animation contains three separate movies, each exhibiting the formation of an igneous rocks in a different environment: a) rocks forming from a deep magma chamber where the slow cooling of magma results in large interlocking crystals; b) rocks forming from a pyroclastic flow with a combination of large and small crystals; and c) rocks with small crystals created from a fast cooling lava. The rock is further modified by bubbles from dissolved gases resulting in vesicles. Each movie concludes with a view of a hand specimen representative of each environment. The animation can be paused and rewound to stress important points.