Rocks and Minerals - Naturally Occurring Chemical Compounds

Rocks and Minerals GRANITE Quartz Where do they come from? Mineral is a naturally occurring substance that is solid and stable at room temperature MINERALS ROCKS Igneous Rocks The Rock Cycle Sedimentary Rocks Metamorphic Rocks Classification Igneous No. 1 When liquid magma cools it crystallizes to form an igneous rock composed of a variety of different minerals. Sedimentary No. 2 Sedimentary rocks form from small weathered particles of other rocks or the weathered shells of sea animals. Wind and rain beating on the faces of exposed rock tend to wear off particles that are blown or washed to a new location." No. Metamorphic Metamorphic Rocks form under intense heat and pressure. Metamorphic rocks start out as igneous rocks, sedimentary rocks or other types of metamorphic rocks, but through heat or pressure, change characteristics such as sheen, tightness of grain and hardness. Generalized Composition Ranges of Igneous Rocks Granite/Rhyolite Diorite Basalt/Gabbro Periodotote 100% Orthoclase 75%E Plagioclase Quartz 50%F Рyrоxine Micas Olivine 25% Amphibole 0% Guide to Rocks and Minerals of Illinois Gabbro Granite One of the most widespread intrusive igneous rocks. Gabbro is another intrusive igneous rock, but it is heavier and darker than granite. Basalt Lamprophyre Basalt is one of the most widely distributed extrusive volcanic rocks. Lamprophyre is the only igneous rock native to Illinois that crops out at the surface. Minerals Extraction Process MINES QUARRIES Mainly hard rock Generally deep • Expensive to operate, so used mainly for high value minerals eg metals O Mainly soft rock O Shallow • Cheaper, so used for low value minerals eg aggregates Once a mineral deposit has been found it has to be extracted from the ground to access the valuable minerals it contains. This can be done by opencast quarrying or underground mining. Certain minerals can also be extracted by pumping. http://granite-worktops-solutions.co.uk/ Source:- http://www.isgs.illinois.edu/maps-data-pub/publications/rocks-min/igneous.shtml http://www.bgs.ac.uk/mineralsuk/minerals You/whereDo.html roCK