Chapter 2, Section 2 How Minerals Form Friday, October 23, 2009 Pages Friday, October 23, 2009 Pages

Objective  Describe the processes by which minerals form.

Vocabulary Words  Magma  Lava  Solution  Vein  Magma  Lava  Solution  Vein

Processes That Form Magma  Minerals can form in two ways:  Through crystallization of melted materials.  Through crystallization of materials dissolved in water.  Crystallization is a process where atoms are arranged to form a material with a crystal structure.  Minerals can form in two ways:  Through crystallization of melted materials.  Through crystallization of materials dissolved in water.  Crystallization is a process where atoms are arranged to form a material with a crystal structure.

Mineral from Magma  Magma is molten material that hardens to form rock.  Lava is magma that reaches the surface.  When lava cools, it hardens and forms rocks.  Magma is molten material that hardens to form rock.  Lava is magma that reaches the surface.  When lava cools, it hardens and forms rocks.

Mineral from Magma -- Cont’d  Crystals form when lava cools and turns from a liquid to solid state.  The size of the crystals depend on:  How fast the magma cools.  The amount of gas the magma contains.  The chemical composition of the magma.  Crystals form when lava cools and turns from a liquid to solid state.  The size of the crystals depend on:  How fast the magma cools.  The amount of gas the magma contains.  The chemical composition of the magma.

Minerals from Magma -- Cont’d  Magma closer to the surface cools faster yielding smaller crystals.  Magma deep below the surface cools slowly yielding larger crystals. Spodumeme crystal can be as large as the size of a telephone pole!

Minerals from Hot Water Solution  A solution is a mixture in which one substance dissolves in another.  When hot water begins to cool, the elements and compounds leave the solution and crystallize to form minerals. Silver as a pure metal -- delicate, treelike crystals are formed.

Veins  A vein is a narrow channel or slab of mineral that’s different from the surrounding rock.  Occurs when pure metals crystallize underground from hot water solutions.

Minerals Formed by Evaporation  Minerals can form from evaporation of a solution. Salt crystals

Where Minerals are Found  Minerals can be found on the Earth’s crust.  These minerals are not distributed evenly.  There are areas of concentration for minerals.

Homework  Workbook 2.2 due on Wednesday,  Vocabulary quiz on 2.2 on Wednesday,  Workbook 2.2 due on Wednesday,  Vocabulary quiz on 2.2 on Wednesday,