Unit 1- Minerals and Rocks

What are the 5 key characteristics of minerals?

1. solid

2. inorganic (never have been alive)

3. occurs naturally

4. have clearly defined chemical compositions

5. have a specific 3D shape or crystal structure

Minerals are the ______

building blocks of rocks

Minerals are formed naturally by…….

Earth’s process of melting, cooling, and solidifying the rock material

What is the rocks cycle?

series of processes that changes one type of rock into another type of rock

How do minerals form?

Minerals form from cooling magma

How do mineral veins form?

different elements and compounds cool at different rates, therefore concentrations of similar elements

What does it mean when minerals have an orderly atomic arrangement?

The atoms are chemically bonded to each other and this arrangement determines the crystalline structure

How do large crystals form?

the result of magma cooling slowly

How do small crystals form?

the result of magma cooling fast

Other properties to identify minerals:

• taste

• smell

• feel

• double refraction

• may react with acids

• florescent

• magnetic

How do scientists organize minerals?

based on the chemical composition

The Dana system groups minerals into 8 classes:

• native

• elements

• silicates

• oxides

• sulfides

• sulfates

• halides

• carbonates

• phosphates

What is the 9th class of the Dana system for?

it is for minerals who don’t fit any of the other groups

How do scientists identify minerals?

• hardness

• streak

• luster

• breakage

• color

• density

• crystal shape

• cleavage

rock

the material that makes up the solid parts of earth

What are the three types of rocks?

• igneous

• sedimentary

• metamorphic

How does Igneous Rock form?

when magma or molten rock cools and hardens

What is sediment

the product of natural processes that break down all types of rock into small fragments

How are sedimentary rocks formed?

when sediments are compressed, cemented together, and hardened

How do metamorphic rocks form?

when the form of an existing rock is changed by certain forces and processed like temperature, pressure, extreme heat, and chemical processes

A rock may not always go through each step of the rock cycle:

• igneous rock may never be exposed to the earth’s surface

• sedimentary rock may break down at Earth’s surface and may become another sedimentary rock

• metamorphic rock may also be changed into a different type of metamorphic rock

Physical Characteristics

reflect the chemical composition of the rock as a whole and the individual minerals that make it up

The rate at which rock weathers and how the rock breaks is determined by….

the chemical stability of the minerals

What did Bowen find?

that different minerals form at different times during the solidification of magma and usually form in the same order

2 Ways Minerals Form

1. characterized by a gradual, continuous formation of minerals that have similar chemical compositions

2. characterized by sudden or discontinuous changes in mineral types

Chemical Stability

a measure of the tendency of a chemical compound to maintain its original chemical composition

Most chemical stability

formed at the lowest temperatures and conditions similar to earths

Least chemical stability

formed at the highest temperatures and conditions very different earths

Joints

evenly spaced zones of weakness

Zones of weakness may also form from….

intense pressure

Decreased pressure allows…..

joints and fractures to open

Particles in crystals are arranged in….

repeating patterns

Ores

rocks that contain valuable minerals

What do atoms effect?

color, shape, hardness, and other properties

Special Properties to identify minerals:

• malleable

• chemical reactions

• radioactive

• magnetic

• fluorescent

Geologists look at the mineral ___,____, and _____ of a rock

composition, color and texture

What are rock-forming minerals?

the 20 minerals that make up most of the rocks of Earth’s crust

extrusive

igneous rocks formed from lava that erupted onto Earth’s surface

intrusive

igneous rocks formed from magma that hardens beneath Earth’s surface

Felsic

light-colored rock that is high in silica

Mafic

dark colored rock that is low in silica

compaction

squeezing of sediment together

erosion

the process of moving broken rock from one location to another

weathering

process of breaking down rock into sediment

deposition

process of laying down sediment

crystalization

cooling & hardening of magma into igneous rocks

composition

chemical makeup or the ingredients of a rock

lithification

process of compacting & glueing sediment

Process of Sedimentary Rock

1. weather

2. erode

3. deposition

4. compaction

5. cementation

Clastic

fragments of rocks and minerals that have been physically transported deposited and then converted into sedimentary rock

Organic

remains of plants and animals that have been converted into sedimentary rock

chemical

direct precipitation of minerals from a solution to form sedimentary rock

How does organic sedimentary rock form

from remnants of living organisms made of calcium carbonate

How does chemical sedimentary rock form

when water evaporates and what is left behind solidifies

foliated

break along lines

have parallel or no touching wavy lines

metamorphism

the process by which heat, pressure, or chemical processes change one type of rock into metamorphic rock

contact metamorphism

occurs when a pool of lava or magma heats the surrounding rock

regional metamorphism

occurs when plates push and grind against each other