Minerals

What is a mineral?

definition: an element or chemical compound that is normally crystalline and is formed as a result of geologic processes

ALL MINERALSshare 5 common

traits!How can you remember them?

COINS!

ALL MINERALS- COINS!Organized

Very specific pattern/arrang

ement of atoms. Inorganic

Not formed of animal or plant

material.

CrystallineHaving a specific internal structure, made of 1 or more

elements.Natural

Not man-made.

SolidNot liquids or

gases.

Minerals can be made up of

individual elements or compounds.

Au Gold

NaClHalite

native mineral: mineral made up of single elements

ex. copper, silver, diamond, sulfur

How do minerals form?

•from molten Earth materials•evaporation of water•heat and pressure

• Although over 4,000 different kinds of minerals exist, only a few dozen are considered common

Mineral Identification

•Hardness•Streak•Cleavage•Luster•Color

Hardness- a mineral’s resistance to scratching

* Moh’s Scale of Hardness

Streak- color of a mineral’s powder

Cleavage

-the tendency of some minerals to break along distinct planes-*if a mineral has cleavage, when it is struck, every fragment will have the same shape

Luster- the way a mineral shines in reflected light

- either metallic or nonmetallic

Color- most noticeable yet least useful Why?- slight impurities can make clear minerals colored.... ex. diamonds

Some other additional tests:

• Fracture – this occurs when the minerals breaks at random spots (not cleavage)

• Specific gravity – ratio of a substance’s weight to the weight of an equal volume of water

There are also special tests used to identify specific mineralsEffervescence - ex. acid test calcite will fizz when hydrochloric acid (HCl) is placed on it.

Magnetism – magnetite is magnetic!

Gemstones – a form of mineral that can be

polished for monetary value

Quartz – when it contains small amounts of iron we call it amethyst

Corundum – is used in emery boards and sand paper; when it contains minor impurities and is polished it is sold as ruby and sapphire

•

Cubic zirconia

• This is a synthetic (man-made) diamond

• It is a durable stone, but not as hard as a real diamond

• Is it a mineral?