1. Minerals & Rocks

2. What is a Mineral? The building block of rocks Naturally occurring (versus synthetic) Inorganic (no C-H bonds) Solid (ice is a mineral then, but water is not) 3. What is a Mineral? Chemical composition & crystalline structure are the two most important properties of a mineral Elements fundamental component of matter Cannot be broken down by ordinary means 88 naturally occurring elements in Earths crust 4. Elements of the Earth 8 elements make up 98% of Earths crust Oxygen Silicon Aluminum Iron Calcium Magnesium Potassium Sodium 5. Elements of the Earth Some few elements ARE minerals (eg: gold) Most are comprised of 2 to 5 elements Held together by + / - electrical charges Many can vary a little is components 88 elements form over 3,500 minerals 9 rock-forming mineral groups 6. Crystals: the crystalline nature of minerals Crystal any substance whose atoms are arranged in a periodic, repeating pattern This pattern is crystalline structure Unit cell the smallest group of atoms making up the unique pattern Crystal face flat surface occurring when a crystal grows freely Reflects light Bonding creates crystal structure 7. Crystal Structures 8. Physical properties of minerals Crystal habit the way crystals aggregate Cleavage Some minerals tend to break along flat surfaces Fracture The way a mineral breaks other than cleavage 9. Physical properties of minerals Hardness Mohs scale 1 to 10, based on minerals Specific gravity Density relative to water Color Obvious, but limited use Streak Color of fine powder Luster The manner it reflects light Other properties 10. Mineral classes and rock-forming minerals Silicates Carbonates Sulfides Sulfates Native elements Halides Oxides Hydroxides Phosphates 11. Mineral classes and rock-forming minerals Silicates Most abundant rock- forming minerals Carbonates Form many sedimentary rocks Phosphates Turquoise Hydroxides Bauxite Halides Table Salt Sulfates Gypsum Sulfides Pyrite Oxides Hematite Native Elements Gold, Silver 12. Silicate minerals compose 92% of Earths Crust 13. Igneous Intrusive (inside) Cool slowly Forms from molten magma Has visible (large) crystals Ex: granite/quartz Extrusive (outside) Cool quickly Forms from lava Has invisible (small) crystals Ex: basalt/pumice/Rhyolite Formed from cooling magma 14. Metamorphic (large change) Formed by heat and pressure (physical) OR By chemical changes which occur through reaction between rock and outside chemical Two types of metamorphism: Contact and regional Contact happens under the surface when magma intrudes into the rock Regional happens on the surface from intense heat and pressure usually during mountain building 15. Metamorphic Coquina Marble 16. Metamorphic Two types form different characteristics Foliated have visible bands Ex: gneiss and slate Non-Foliated have no visible bands marble 17. Sedimentary Formed from Sediment created by weathering and erosion of existing rocks which is then compacted and cemented Weathering and erosion Particles, altered, or dissolved materials Transported and deposited Compaction Lithification (glueing together) Four Types Clastic Chemical Organic Bioclastic 18. Clastic Easily seen fragments Conglomerate Rounded particles Breccia Angled particles Not easily seen fragments Sand sized Sandstone Clay sized Shale/siltstone 19. Chemical Formed by Chemical Processes Evaporation Solid forms when water is evaporated Halite (salt)/Gypsum Precipitate Forms when two liquids are mixed limestone 20. Bioclastic Are formed from living organisms shell fragments Hard-shelled organisms Clams, corals, oysters, etc. Carbonate skeletons 21. Organic Formed from living organisms - plants/animals Coal made from plants Limestone made from shells 22. Rock Cycle Magma Igneous Weathering & erosion sedimentsSedimentary Rock Metamorphic Rock Heat & Pressure Compaction & cementation Heat & Pressure Weathering & erosion 23. Videos This is a super website for mineral identification http://www.rocksforkids.com/RFK/identificati on.html#Field