The Rock Cycle

Elements in the Earth’s ATMOSPHERE Amount Nitrogen 78.1 % Oxygen 20.9 % Argon 0.96 %

Elements in the Earth’s OCEANS Amount Oxygen 85.84 % Hydrogen 10.82 % Chlorine 1.94 % Sodium 1.08 % Magnesium 0.1292 %

Elements in the Earth’s CRUST Oxygen Silicon Aluminum Iron Calcium Amount 47 % 28.2 % 8.23 % 5.63 % 3.5 %

IGNEOUS ROCKS Forms from cooled lava. Most have crystals… the size of the crystal depends on how fast the lava cooled. - Slow cooling = large crystals - Fast cooling = small to microscopic Some rocks have pores (like a sponge) from the gases in the lava escaping during the cooling process.

Uses of Igneous Rocks Road building materials Gravestones Creating lasting monuments Used as an abrasive in polish things. For trim and decoration in buildings. Decorative landscape stone. Jewelry

IGNEOUS ROCKS Granite Obsidian Pumice Gabbro

Igneous rock forms in two ways! Intrusive - Forms from magma cooling and solidifying inside the earth’s crust. Extrusive - Forms from lava cooling and solidifying outside of the earth’s crust.

SEDIMENTARY ROCKS Formed from weathered igneous and metamorphic rocks that are compacted and cemented together! Usually layers can be seen. Some are conglomerates… i.e. you can see smaller rocks or shells embedded.

Uses of Sedimentary Rocks Gypsum is used to make plaster of Paris and in drywall. Sandstone and limestone are used as building stones. Limestone is also used for hard core cement roads.

SEDIMENTARY ROCKS Conglomerate Shale Limestone Banded-Sandstone

METAMORPHIC ROCKS Formed within the Earth… rocks that undergo an extreme amount of heat and pressure. These rocks are usually very dense rocks.

Uses of Metamorphic Rocks Used for pool table tops Carved into statues Buildings materials (floor tiles roofing tiles and counter tops) Jewelry = Diamonds

METAMORPHIC ROCKS Marble Slate Mica Schist Quartzite

Rock Cycle

The Importance of Rocks and Minerals Igneous Obsidian Used in making arrowheads and knives Basalt Used in road building materials Pumice Used in scouring, scrubbing, and polishing materials Granite Used for buildings, monuments, and tombstones

The Importance of Rocks and Minerals Sedimentary Sandstone Used in the building industry for houses Gypsum (mineral) is used to make plaster of Paris and in drywall Limestone is also used for hard core cement roads.

The Importance of Rocks and Minerals Metamorphic Marble Used in building, floors, tile in bathrooms Slate Used for roofs, chalkboards, patio walks and pool tables

The Importance of Rocks and Minerals Calcite Used in cements and mortars and the production of lime Quartz Used in making glass, electrical components, and optical lenses

Physical Properties of Rocks and Minerals

Minerals A mineral is… Naturally occurring Inorganic- (made up of none living things) Definite chemical composition & crystal structure Solid All physical properties of minerals come from the “internal arrangement of atoms”

Mineral Identification Tests The Streak Test The Color Test The Luster Test Hardness (Moh’s Scale) Cleavage Crystal Shape Reactions with Acids Specific gravity

The Streak Test The color of the powdered mineral performed by rubbing the unknown mineral on an unglazed tile.

The Luster Test The way a mineral shines or doesn't shine The only way to really learn the different luster's is to see them for yourself. 2 Types of Luster Metallic and Non-Metallic Metallic Luster Rocks look like shiny metal Ex. Hematite

Non-Metallic Luster Non-metallic- all the other ways that a mineral can shine Glassy- shines like a piece of broken glass (most common non-metallic) Dull/earthy- no shine at all Resinous/waxy- looks like a piece of plastic or dried glue Pearly- looks oily it may have a slight rainbow like an oil slick on water. Also looks like the inside of some clam shells Adamantine- brilliant, sparkling shine like a diamond

Color Test Color is used to determine the type of rock but it is not always reliable. Sulfur is (almost) always yellow, and there are a few others, but not many minerals have a fixed color. Small amounts of impurities can drastically change a mineral's color.

Hardness Test Hardness- a minerals resistance to scratching. This should not be confused with brittleness. A diamond is very hard and will scratch a hammer but a hammer will smash a diamond.

Moh’s Scale of Hardness Talc (Softest) Gypsum Calcite Fluorite Apatite Feldspar (AKA Albite) Quartz Topaz Corundum Diamond (Hardest)

Cleavage Test Cleavage –The rocks will break along flat surfaces or… Cubic- Rocks will break into cubes.

Crystal Formation Minerals will grow crystal formations when given time & space to grow. Can be recognized by their beautiful regular shapes once you have seen a few examples. Quartz Crystal Formation

Miscellaneous Tests Acid- Calcite and powdered dolomite will Effervescence (fizz) in diluted hydrochloric acid (HCl) Smell- Sphalerite will give off a rotten-egg smell when streaked on a streak plate. Magnetism- Magnetite (AKA Lodestone) will pick up paper clips

Miscellaneous Tests Cont. Taste- Halite is rock salt and will taste salty. Fluorescence- some minerals (mostly forms of calcite) will glow in fluorescent colors under a black (UV) light. Double refraction- some clear forms of calcite (Iceland Spar) will make a double image of words.

Specific gravity Specific gravity indicates how many times more the mineral weighs compared to an equal amount of water . Since water has a density of 1 gram/cm3, and since all of the units cancel, specific gravity is the same number as density but without any units. Remember… Density = Mass / Volume Density is how much matter packed in a space.