ROCKS

BellworkDescribe 7 objects around the classroom that contain minerals.You can refer to Appendix H of your textbook for guidance. Pg. 918

MINERALS

What is a Mineral?Short Video 3:38http://app.discoveryeducation.com/player/?assetGuid=C068FDD9-CB53-41DB-AFD3-0309E0C1A43C&fromMyDe=0&isPrinterFriendly=0&provider=&isLessonFromHealth=0&productcode=US&isAssigned=false&includeHeader=YES&homeworkGuid=

MineralsEarths crust is composed of about 3000 mineralsMinerals: form from magma or solution form rocks have a chemical composition crystalline StructureMost abundant Feldspar and QuartzHumans use and make products out of mineralsDefinite Crystalline StructureAtoms in minerals are arranged in geometric patterns6 major crystal systems

Mohs' hardness scale:1 = softest10 = hardest

Minerals identified by physical and chemical propertiesColor (physical characteristic)Luster - (metalic, dull, pearly, waxy, silky)Texture (smooth, rough, ragged, greasy, soapy, or glassy)Streak (color of its powder)Hardness (does it scratch easily?)Cleavage (splits easily & evenly)Fracture (breaks rough or ragged edges)Density and Specific Gravity (atomic weight and structure)

GemsGems are rare, precious, highly prized mineral that can be cut, polished, and used for jewelry.Rubies, emeralds, and diamonds

What is the hardest mineral?Diamond scratches all common materials

ROCKS

What is a Rock?Naturally occurring mixtures of minerals. Sometimes includes organic matterWhat is the difference between a ROCK and a MINERAL?Rocks are made up of ONE or MORE minerals. Minerals are an inorganic substance in natureOccurs naturally; solidHas its own characteristics appearance and chemical compositionMined or extracted from the groundDoes a rock stay the same rock forever?NO!Rocks are continually changed by many processes such as:WeatheringErosionCompactionCementationMeltingCooling

Rocks are divided into 3 groups based on how they are formed:

IGNEOUSSEDIMENTARYMETAMORPHIC

Earth materials change back and forth among the difference types of rocks.The Rock CycleIgneous Rocks Ignis = Latin for fireFormed from the cooling of either magma or lavaThe most abundant type of rockClassified according to their origin and composition

2 Types of Igneous RockIN-TRUSIVE (inside) / below groundFrom magmaCool slowlyLarge crystal grains

EXTRUSIVE (outside)/above groundFrom lavaSmall/no crystalsCool quickly

Click here.. Video 4:09 Our World - The Rock Cycle

http://www.youtube.com/watch?v=SRaInMDNyE8

Peridotite: Intrusive or Extrusive? Why?

Granite: Intrusive or Extrusive? Why?

Obsidian: Intrusive or Extrusive? Why?

Sedimentary RocksFormed from sediments:rock fragments,mineral grains,animal & plant remainsPressed or cemented together Or sediments precipitate out of a solution. Moved by wind, water, ice or gravityOnly kind of rock containing fossils Form horizontal layers

3 Sedimentary CategoriesClastic rock formed by mechanical weatheringChemical rock when rocks dissolve, the solution cools or evaporatesOrganic rock formed from compaction of plant remainsWhat turns sediments into solid rock?

erosion & depositioncompactioncementation

Exp. Grand Canyon

Metamorphic Rocks meta=change morphe=formRocks that change due to intense temperature and pressure

2 Textural Groups:FoliatedWavy layers and bands of mineralsFlat or needlelike crystals perpendicular to the pressureNonfoliatedLack mineral grains with long axis in one directionBlocky crystal shapesWhat occurs in the Earth to change these rocks?Pressure from overlying rock layers High heat, but not enough to melt the rock Rocks may be flattened or bent or atoms may be exchanged to form new minerals.You can think of metamorphic rocks as a squished peanut butter & jelly sandwich in your lunch.

Bill Nye Video 23:05http://www.youtube.com/watch?v=cJA-QJmk4Z4&feature=player_embedded