Rocks & Minerals ROCKS & MINERALS

What is a mineral?

Solid – can not be a liquid or a gas

Naturally Occuring- found in nature; not man-made

Inorganic- is not alive and never was; non-living

Fixed Composition- has a chemical formula, most are

formed from compounds or 2 or more elements; some

minerals consist of 1 element

Crystal Form- a definite structure in which atoms are

arranged

Minerals must be:

• Naturally occurring

made from non-

living things

(fossils & coal are made

from living things that

died so are not

considered minerals)

Not man made

Minerals must be:

• Solid

– Have a fixed shape

and volume

– Never living-

inorganic

Minerals must have:

• Have a definite

crystal structure

– particles line up in a

regular, repeating

pattern.

– flat sides called faces,

that meet at sharp

edges and corners.

http://vasichkominerals.com/

Minerals must have:

• A definite chemical composition

– Always contains

certain elements in the same proportion.

– Almost all minerals are compounds, (two or more different elements chemically joined).

http://www.eas.slu.edu/People/Students/woodhull/uraninite.html

Determine if the following is a

mineral or a non-moneral

Topaz ~ Diamonds

~ Fossils

Coal ~ Quartz

~ Iceberg

Pearls ~Bone

~ Gold

Talc ~ Granite

~ Wood

Answers

Minerals

• ~ Gold

• ~Topaz

• ~ Quartz

• ~ Talc

• ~Iceberg

• ~Diamonds

Non Minerals

• ~ wood- once living

• ~fossils- once living

• ~bone- living material

• ~granite – intrusive igneous

rock

• ~ pearls – made by oysters

• ~coal- once living,

sedimentary rock

Minerals Review

• All minerals must:

– Occur naturally in nature

– Inorganic solid

– Crystal structure

– Definite chemical composition

http://nature.ca/museum/press/2006/pr06-02-07_minstucson_e.cfm

Properties of Minerals

• Hardness A measure of how

easily a mineral can be

scratched.

http://www.info-diamond.co.uk

Properties of Minerals

• Density • Minerals will have a

certain density

regardless of the size of

the sample.

• Each mineral has its

own density called

specific gravity

http://www.astronomynotes.com/cosmolgy/

Properties of Minerals

• Luster • The way a mineral

reflects light.

• Can be metallic or

non-metallic.

• Shiny or dull.

• waxy, pearly, glassy.

This is a gem stone called

tourmaline it has a glassy

luster

Properties of Minerals

• Streak • The color of its

powder.

• Not always the same

as the color of the

mineral.

http://geology.csupomona.edu/alert/mineral/streak.htm

Properties of Minerals

• Color

first thing noticed

about minerals

http://www.nmnh.si.edu/rtp/students/2004/virtualposters/poster

Rocks classification

• Texture

• Grain

• Minerals

• Color

• Origin of rocks

http://geology.com/rock-tumbler/tumbling-rough.shtml

Rock classification

• Texture is how a rock

looks and feels

• texture in rocks is

determined by the

size, shape, and

pattern of a rocks

grains.

ocal.wasp.uwa.edu.au/.../rock/rock16.jpeg

Rock Classification

• Grain

– Size -- large, small

– Shape --smooth, rough,

round jagged

– Pattern – rows, waves,

swirls, beads or

random patterns

http://www.union.edu/PUBLIC/GEODEPT/COURSES/geo-10/metamorphic.htm

Rock classification

• Mineral

composition

– Rocks are made of

more than one

mineral

blue.utb.edu/.../PHYS1417SPR00/Unit3Lec.html

Rock classification • Color rocks

come in all sorts

of colors

Rocks & Minerals

Rock Classification • Origin of rocks

• How were the

rocks formed

- magma

- erosion and

layering

- heat and pressure

Origin of rocks

• Igneous rocks are

formed from the

cooling of magma or

lava

– Lava is magma that

reaches the earth’s

surface

www.outreach.canterbury.ac.nz/.../igneous.jpg

Origin of rocks

• Sedimentary rocks

are formed from other

rocks that are broken

into small particles

and moved by erosion

(wind or water)

• The particles are

squeezed or cemented

together

• Rocks are layered

www.energyinst.org.uk/education/glossary/

Origin of rocks

• Metamorphic rocks are formed from other rocks

• Rocks have been pushed deep into the earth’s crust

• Pressure from the earth above and heat from the mantle below cause them to change shape, color, grain and crystal structure

http://www.classzone.com/books/earth_science/terc/content/visualizations/es0607/es06

07page01.cfm?chapter_no=visualization

Rock cycle

http://www.classzone.com/books/earth_science/terc/content/investigati

ons/es0602/es0602page02.cfm