Alright friends, a couple of people asked me to ID some rocks for them, but I'm not really comfortable making guesses from what I get as far as online descriptions go, so I'm hoping to arm you with the ability to figure it out for yourselves. Hope this helps someone. First up, igneous rocks. These are rocks that are made from lava or magma. They are grouped into two basic types of texture and three types of composition for classification purposes. All of these rocks can be identified by sight alone. The texture of the rock is decided by how it cools. If a volcano spews out lava, it cools very quickly and makes a rock that appears to be of a uniform color, like the rope-y looking black rock being formed daily in Hawaii (basalt). If magma cools down at a much slower pace under the surface of the earth, the different minerals that make up the magma have time to form crystals, resulting in rocks like granite. Let's just call the the fast coolers extrusive and the quick coolers intrusive for now. We can gather a fairly accurate idea of the rocks mineral composition by color alone. Black igneous rocks are referred to as mafic. A typical sample would be primarily made of pyroxine with some amphibole and plagioclase, maybe even a little olivine. Mostly white igneous rocks are called felsic and contain a higher level of plagioclase along with minerals like quartz and orthoclase. Rocks that are in the grey area between the two extremes are referred to as intermediate. That's smart. Now get ready for the fun part....I've got a table that lets you identify igneous rocks and deduce their mineral content with just a quick glance. Hold on to your butts. Redirect Notice Next time, we get started with some mineral identification. BWAHAHAHA!