All Minerals are rocks. … But not all rocks are minerals!!

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Compare these 2 Samples: Both are rocks, but only one is a mineral…WHY?

Mineral Characteristics Naturally Occurring Form in nature NO human help Olivine

Mineral Characteristics Inorganic: Not made from living things. chalcenthite

Mineral Characteristics galena Crystal Structure: Repeating pattern of atoms Natrolite

Graphite

Mineral Characteristics Solid: Consistent Crystal Shape Density gypsum

Mineral Characteristics Consistent Chemical Composition: Elements in a constant ratio Example: FeS2 same as Fe10S20 Rainbow pyrite

Compare these 2 Samples: coal Both are rocks, but only one is a mineral…WHY?

Crystal: A solid in which the atoms are arranged in orderly, repeating patterns.

Shape and appearance depend on: Space for development Temperature they develop Environment around them

Crystals form by 2 methods: 1. Cooling Magma: SPEED: The faster the magma cools, the smaller the crystal AREA: The larger the area, the larger the crystal Hematite

Crystals form by 2 methods: 1. Crystals from solution: When water evaporates Crystals form Example: Utah Salt Flats

6 common Patterns

1. Cuboidal All axes are 90 degrees All faces are the same size Example: Halite

2. Hexagonal 6 rectangle faces Angles are 120 degrees Example: Quartz, Beryl                                                                             

3. Tetragonal “Rectangle Sides” Axes are 90 degree angles                                                                    “Rectangle Sides” Axes are 90 degree angles Example: Zircon

4. Orthrombic 90 degree axes More brick shaped than tetragonal                                                                                                                       

5. Monoclinic Only 1 90 degree angle

6. Triclinic                                                                           Unequal in ALL dimensions