1-3 Formation and Mining of Minerals Objectives: 1.Describe the environments in which minerals form. 2.Compare and contrast the different types of mining.

Formation of Minerals The environment determines minerals properties. Types: evaporating saltwater, limestones, metamorphism, hot-water solution, pegmatites, plutons

Evaporating Saltwater Minerals Form when a body of salt water dries up. Halite Gypsum

Limestone Minerals Form when surface and ground water carry dissolved minerals into lakes and seas. Calcite Dolomite

Metamorphic Minerals Form when heat and pressure changes the structure of existing minerals Garnet Magnetite

Hot-water Solution Minerals Form when water heated by magma dissolves metals and other minerals into a solution. These crystallize when the water evaporates. Gold Sulfur

Pegmatite Minerals Tear shaped bodies of magma take a long time to cool – therefore they form large crystals. Tourmaline Topaz

Pluton Minerals Magma that is close to the surface, but far enough underground that it is well insulated and cools slowly. Quartz Mica

Mining Ore – a mineral deposit large enough to be mined for profit.

Surface Mining The removal of minerals or other materials at or near Earth’s surface. Open pit mines Quarries Strip mines Copper and aluminum are mined this way.

Deep Mining The removal of minerals or other materials from deep within the earth. Diamonds and coal are commonly mined this way.

Value of Minerals Gems – minerals that are very rare and attractive. They are admired for their beauty rather than their usefulness. Metals – from mineral ores – chalcopyrite (copper), galena (lead), beryl (beryllium), chromite (chromium)

Responsible Mining Reclamation – returns a mined area to its natural state after mining is complete. It has been required since the 1970’s and has improved on the habitat of many animals and plants.