Transcript Mineral
“Dynamic” Earth Dynamic continually changing Why is “dynamic” a good description of the planet? How is the planet “dynamic”? Give examples Because of the changes, is earth alive? Layers of the Earth Rocks and Minerals found here. Melted mineral soup here. A. Continental Crust B. Core C. Mantle D. Magma What layer is below the crust? Brainstorm!!! Rocks Minerals Rock A solid mixture of minerals that was formed in the Earth’s crust Atoms Elements smallest Compounds Minerals (crystals) ROCKS largest Order the choices from simplest to most complex… 1) 2) 3) 4) Compound Rock Atom Mineral So, what is a mineral? What are the characteristics of all minerals? Minerals form 2 ways: When lava cools and crystallizes into a solid When elements that are dissolved in water, crystallize. Mineral A solid natural material that has a crystal form and its own set of properties Small crystals form when the mineral cools quickly. Large crystals form when the mineral cools slowly. How do larger crystals form? A. Larger crystals form when magma cools quickly or when water evaporates quickly. B. Larger crystals form when magma cools slowly or when water evaporates slowly. 1. A mineral occurs naturally. 2. A mineral is solid. 3. A mineral has a definite chemical composition. 4. A mineral’s atoms are arranged in an orderly pattern forming crystals. 5. A mineral is inorganic (was never alive) Characteristics of Minerals 1. Formed by natural process – occurs on or inside earth 2. Inorganic (not living) – not made out of living things 3. Has a definite chemical composition 4. Orderly arrangement of atoms in a repeated pattern forming Coal is a fossil fuel… is it a mineral too? Formed by natural process – occurs on or inside earth Has a definite chemical composition Orderly arrangement of atoms in a repeated pattern forming crystals. Inorganic Solid Coal is formed by plant and animal material (ORGANIC) breaking down and with pressure over time turning to a solid. Of the almost 4000 known minerals, only about 30 are common. The most common are quartz,feldspar,mica, and calcite. These minerals make up most of the rocks found in the Earth’s crust. In fact, over 60% of the Earth’s crust is made up of the family of minerals known as feldspar! To be able to identify these and other minerals, we need to look at the properties used to separate and distinguish these minerals. 5 Mineral Groups Element = Uncombined Element (straight off the periodic chart) Silicate = Silicon (Si) + Oxygen (O) + ? Carbonate = Carbon (C ) + Oxygen (O) + ? Oxide = ANY METAL + Oxygen (O) Sulfide = ANY METAL + Sulfur (S) Various Crystal Shapes Crystal shape can be a useful property to identify minerals if the minerals have had the time and space to form crystals. Most mineral grains that are found in rocks, lack the room to grow. Color is the most easily observed mineral property and the least useful! Many minerals have a similar color. For example, pure quartz is colorless or white, impurities can make the mineral rose, purple or pink! Luster: the way a mineral reflects light Metallic/Nonmetallic Luster Hardness: how easily a mineral can be scratched MOHS Scale: list of hardness of 10 minerals (soft=1; hard=10) Softest is talc Hardest is diamond Streak: the color of a mineral in its powder form Streak Color for a Few Common Minerals •Graphite - Black •Pyrite - Black •Magnetite - Black •Chalcopyrite - Black •Galena - Gray •Limonite - Yellow-brown •Hematite - Red-brown Examples of Streak CLEAVAGE One of two ways a mineral breaks 1. Cleavage – minerals break into smooth flat surfaces 2. Fracture – minerals break into rough uneven surfaces Examples of Cleavage Magnetic Malleable Radioactive Flourescence Taste Discuss the following! Does this mineral show cleavage or fracture? Of the four most common minerals, which is the highest hardness? Minerals are the combinations of 8 Main Elements (O, Si, Al, Fe, Ca, Na, K, Mg) (activity) On a clean sheet in your notebook form two columns with 5 blocks in each… Building Minerals SiO2=quartz FeS2 = pyrite