How Minerals Form Minerals Chapter 4 Sec 2

Minerals Form in Two Ways Crystallization of Melted Materials (i.e. magma and lava) Crystallization of Materials Dissolved in Water (In Solution)

Crystallization: the process by which atoms are arranged to form a material with a crystal shape….. Crystallization: the process by which atoms are arranged to form a material with a crystal shape….. Note: Fully formed crystals are rare- most are only partially formed because they form the same time as others Note: Fully formed crystals are rare- most are only partially formed because they form the same time as others

Crystallization of Melted Materials (Magma & Lava) 1. Magma Cools inside the crust or lava hardens and cools on the surface of Earth 2. These liquid crystals cool and form crystals (repeating pattern of atoms- either elements or compounds) Size depends on ….

3 Things Impact the Size of the Crystals 1. Rate at which magma/lava cools Slow=large crystals-tend to be deep below the surface Fast=small crystals-on or near surface- crystals don ’ t have enough time to add more to the repeating pattern 2. Amount of Gas Magma Contains Lots of gas interferes with the atom ’ s ability to connect together 3. Chemical Composition of Magma Compounds form bigger crystals than elements

A solution is… A mixture in which one substance (the solute) is dissolved in another (the solvent). A mixture in which one substance (the solute) is dissolved in another (the solvent)._______________________________ Minerals can form 2 Ways from a Solution 1. materials dissolved in solution come out of solution 1. materials dissolved in solution come out of solution 2. the solvent evaporates-leaving the minerals behind 2. the solvent evaporates-leaving the minerals behind

Crystallization of Materials Dissolved in Water (in solution) 1. Elements dissolve in hot water heated by the magma and form solutions 2. Solution cools 3. Elements and compounds leave the solution and crystallize into minerals, often forming veins –Vein-narrow channel or slab of mineral that is different from surrounding rock

Mineral Veins:

Mineral Solutions also occur near the mid- ocean ridge: 1. Water seeps down through cracks in ocean floor 2. It is heated by magma 3. Elements from the crust are dissolved into solution 4. Rush upward due to density 5. Travels out of vents or chimneys 6. Cold water helps minerals crystallize 7. Mineral deposits are found on the ocean floor

Hydrothermal Vents

Minerals Formed by Evaporation These minerals are formed when the water evaporates and leaves the mineral that was in solution behind These minerals are formed when the water evaporates and leaves the mineral that was in solution behind Examples: Examples: –Deposits of Halite formed when ancient seas evaporated –Also, Gypsum, calcite, and potassium

Mineral Resources Chapter 4 Sec 3

Uses of Minerals Metals Metals Gemstones Gemstones Material used to make useful products Material used to make useful products

Gemstones A gemstone is a hard, colorful mineral that has a brilliant or glassy luster. A gemstone is a hard, colorful mineral that has a brilliant or glassy luster. Valued for their color, luster, durability, and because they are rare. Valued for their color, luster, durability, and because they are rare. Called a gem once it is cut and polished. Called a gem once it is cut and polished. Used for jewelry, decoration, mechanical parts, grinding and polishing Used for jewelry, decoration, mechanical parts, grinding and polishing

Metals Minerals are the sources of some metals- aluminum, iron, copper, or silver Minerals are the sources of some metals- aluminum, iron, copper, or silver Useful for their unique properties of ductility, malleability, and strength Useful for their unique properties of ductility, malleability, and strength

Other Useful Minerals Foods Foods Medicines Medicines Fertilizers Fertilizers Building materials Building materials Specific Examples Specific Examples –talc=talcum powder –Fluorite=used in aluminum and steel –Calcite=microscopes –Quartz-used to make glass, electronic equipment, and watches

Ore A rock that contains a metal or other economically useful mineral A rock that contains a metal or other economically useful mineral

Finding Useful Minerals Prospecting Prospecting –A prospector is anyone who searches, or propsects, for an ore deposit –Look for Earth ’ s features- such as types of rocks on the surface, plants growing, and types of elements found in water sources

Extracting Useful Minerals 3 types of mines 3 types of mines –Strip mine  Earth moving equipment scrapes away soil to expose ore –Open pit mine  Miners dig an open pit mine to remove deposits and then follow them below the surface (approx 1 km wide and deep) –Shaft mine  To follow veins miners dig a network of tunnels (shaft mines) Mining can cause quiet a bit of damage to the environment Mining can cause quiet a bit of damage to the environment

Smelting The process by which an ore is melted to separate the useful metal from other elements that the ore contains The process by which an ore is melted to separate the useful metal from other elements that the ore contains