Rocks N Minerals

ROCKS N MINERALSRockin in the USA!!!!

3 Major Rock Types

1. Igneous Rock 2. Sedimentary Rock 3. Metamorphic Rock

Igneous Rock Means “From Fire” Forms when magma cools

and hardens Lava rock

2 Groups of Igneous Rocks 1. Intrusive Igneous Rock:

Cooling of magma deep below the earth’s surface.Have large crystalline grains

2. Extrusive Igneous Rock: Rapid cooling of lava on the earth’s surface.Fine grained rock

Igneous Texture Size of the crystalline grains in rock Depends on rate of cooling

Slower cooling = more grainsGranite

Intrusive have larger grains Porphyry: has a mixture of large and

small crystals Igneous rocks cooled very fast will look

like glass. Obsidian

Igneous Composition Determined by composition of

magma the rock was formed from

Divided into 3 categories:1. Felsic2. Mafic3. Diorite

Felsic High in silica Light coloring of their mineral

crystals Ex. Granite and obsidian

Mafic Low in silica but rich in iron Have dark colored mineral crystals Ex. Basalt and gabbro

Diorite Include little or no quartz Contain coarse grain diorite

Warm Up Questions??? 1. What are the three main types of

rocks? 2. Slow cooling of a rock is called

____________. 3. Fast cooling of a rock is

called______________. 4. Please name one rock which cools

slowly. 5. Please name one rock that cools

quickly. 6. Which rocks make up continental

and oceanic crust?

Forces of nature break down rocks into small particles called sediment

Wind, water, and ice

Weathering

Erosion Movement of

particles of rock due to weathering.

Particles are loosened and moved

Sedimentary Rocks Rocks are broken down due to

erosion Very small rock sediments are

collected in streams, rivers, and oceans.

Sediments compact Harden and form new rocks

Compaction and Cementation

Processes that form sedimentary rocks

Various types of rock sediments accumulate

Compact and become thick layers

Weight and pressure cement sediments into solid rock

Minerals left between sediments act as cement

Sedimentary Rock Types 1. Clastic: separate fragments

become compacted into solid rock.

2. Chemical: Form from dissolved minerals

3. Organic: form from the remains of organisms.

Clastic Sed. Rocks 1. Conglomerate: Rock

composed of round, pebble sized fragments.

2. Breccia: Rock composed of pebble sized fragments with sharp, angular corners.

Chemical Sed. Rocks Minerals

dissolve in water

Leave behind deposits

Dry and harden into rocks

Ex. Rock Salt

Organic Sed. Rocks Formed from

the remains of living things

Ex. Coal, and Chalk

Stratification Layering of

sedimentary rocks

Occurs when there is a change of sediment being deposited

Usually found in sedimentary rocks

Animal or plant is buried Sediments pile up and harden Hard bones and teeth dissolve This leaves an impression in the

rock

Fossils

Metamorphic Rock Changing of one type of rock

to another by heat, pressure, and chemical processes.

Form deep beneath the surface

All metamorphic rock is formed from existing igneous, sedimentary, or metamorphic rock.

Metamorphic Cont. Heat and

pressure semi melt the rock and cause certain minerals to change into other chemicals.

Parallel bands running through the rock

Classification of Met. Rock Classified according to structure Foliated: have visible parallel

bands Mineral bands separate by density under pressure

Slate, schist, and gneiss Unfoliated: without visible

bandsQuartzite and marble

Met. Rock Table

Rock Cycle Any of the three major types

can change into another type. Geological forces have the

ability to change one rock type to another.

Rocks are recycled throughout these three forms

Rock Cycle Explained

Rock Cycle Fire

Question 1 Please explain how igneous

rock can turn into sedimentary rock during the rock cycle.

Question 2 Please explain how

sedimentary rock turns into igneous rock.

Question 3 Please explain how sedimentary

rock can turn into metamorphic rock.

Question 4 Please explain how it is possible

for metamorphic rock to become another metamorphic rock.

Mr. Parr Rock Cycle

Mr. Lee Rock Cycle

Minerals

Minerals A natural, inorganic,

crystalline solid. The basic elements of the

earth’s crust. Over 3,000 total 20 Common

Characteristics of Minerals Each mineral has specific properties Mineral Properties:

1. Color2. Luster3. Streak4. Cleavage and Fracture5. Hardness6. Crystalline Shape7. Density8. Magnetism

Color Unreliable identification Some minerals have distinct

colors BUT Some minerals will change color

when exposed to different elements.

Luster Light refracted from the surface

of a mineral Metallic and nonmetallic luster Glassy Waxy Pearly Brilliant- Diamond

Streak Color of the mineral in

powder form Rub the mineral against a

ceramic tile and observe the streak

May not be same color as a larger piece of the mineral

Cleavage and Fracture Cleavage: How a mineral

will break along its flat surfaces.

Fracture: Irregular breaking of a mineral.

Depends on Bonding of elements

Magnetism Is the

mineral magnetic???

Hardness The ability of a mineral to resist

scratching Determined by the Mineral

Hardness ScaleScale of 1-10 (10=hardest)

Mineral Hardness Scale 1. Talc 2. Gypsum 3. Calcite 4. Fluorite 5. Apatite 6. Orthoclase 7. Quartz 8. Topaz 9. Corundum 10. Diamond

The Gypsy Came From Asia Often Questioning The Crazy Directions

•           Finger Nail (H = 2.5)•           Penny (H = 3)•           Knife Blade (H = 5.5)