All minerals are formed by natural processes, which occur on or inside Earth with no input from humans Ex: Salt forms from the natural

evaporation of seawater (mineral-halite) Minerals are inorganic

Aren’t made by life processes Minerals are an element or compound

with a definite chemical composition Ex: Halite-NaCl (gives a distinct taste to

food)

Minerals are crystalline solids All solids have a definite volume and

shape Not all solids are minerals crystalline-atoms are arranged in a

pattern Graphite-arranged in layers Opal-not a mineral because it doesn’t

have a pattern

Is a solid in which the atoms are arranged in orderly, repeating patterns

Crystals with a smooth surface and regular shape developed in a freely open space Ex: clear quartz (hexagonal shape)

Crystals whose shape can’t be seen on the outside have developed in a tight space Ex: rose quartz

1. Hexagonal: Ex: Clear Quartz Surfaces form 120° and 60° angles

2. Orthorhombic- Ex: Barite Dimensions are unequal-brick like shape

3. Monoclinic: Ex: Orthoclase Unequal dimensions 1 right angle forms

4. Triclinic: Ex: rhodonite Exhibits the least symmetry Unequal in all dimensions

5. Cubic: Ex: Flourite Crystals are equal in size like a cube all three dimensions are equal6. Tetragonal: Ex: Zircon Like a cubic crystal One dimension is longer or shorter

than the other too

Natural processes form minerals 2 ways crystals form1.From Magma: Magma cools-atoms move closer

together Combine into compounds Atoms arrange themselves into orderly,

repeating patterns Type and amount of elements

determine which mineral will form

Size of crystals depends on how quickly magma cools

Large crystals form when magma cools slowly Small crystals form when magma cools quickly2. From Solution Crystals form from minerals dissolved in water Evaporation of H20 causes ions to come

together (halite) If too much of a substance is dissolved in

water, ions will come together forming crystals of that substance (don’t need evaporation)

8 elements form 98% of Earth’s crust Silicates

most rock-forming minerals belong to this group

Minerals that contain silicon, oxygen and one or more other elements

Silicon and oxygen 2 most abundant elements in Earth’s crust

Carbonates Contain carbon, and oxygen and other

elements Are rock-forming minerals

Every mineral has unique physical properties that distinguish them from each other

There are 7 properties scientists look at Every property you observe in a

mineral is a clue to its identity1.Mineral Appearance: Color and appearance Can not just look at these 2 properties

because minerals can have the same color and shape

2. Hardness How easily a mineral can be scratched Talc is soft and can be scratched with

your fingernail Diamonds are the hardest mineral Mohs scale

Lists the hardness of ten minerals Softest talc hardness =1 Hardest diamond=10 Depending on the item you can scratch the

mineral with, will tell you its value and what kind of mineral it is

3. Luster The way a mineral reflects light Can be metallic-shine like metal Can be nonmetallic-does not shine like metal

Ex: quartz, calcite, halite, flourite

4. Specific Gravity Is the ratio of its weight compared with the

weight of an equal volume of water Expressed as a number Ex: gold’s specific gravity=19 This means that it is 19 times heavier than

H2O

Heft is a term used to describe how heavy a mineral sample feels

5. Streak Is the color of a mineral when it is in a

powdered form Scratched on a piece of unglazed

porcelain tile Streak test only works if the mineral is

softer than the tile

6. Cleavage Minerals that break along a smooth,

flat surface Ex: Mica-breaks apart in smooth layers

7. Fracture Break with uneven, rough, or jagged

surfaces Ex: Quartz

Highly prized minerals because they are rare and beautiful

Most are special varieties of a particular mineral

Clearer, brighter or more colorful than original mineral

Table 2

Some gems are spectacular and play a role in history Ex: Cullinan Diamond

Was cut into 9 main stones and 96 smaller stones

Part of British crown jewels Ex: blue Hope diamond

Gained reputation for bringing bad luck

Some gems are useful Diamonds used as industrial abrasives

and cutting tools Rubies used to produce specific types

of laser light Quartz crystals used in electronics and

as timepieces Most industrial diamonds and other

gems are synthetic-made by humans

Mineral or rock is an ore if it contains a useful substance that can be mined at a profit

Ex: Hematite-contains iron Iron used to make pans, ships Aluminum comes from the ore bauxite Refining of aluminum

Aluminum oxide powder is separated from bauxite Powder is converted into molten aluminum by smelting-

substance is melted to separate it from unwanted materials that remain

Aluminum used to make bicycles, cans, foil

Mineral deposits left behind that fill in the open spaces created by weaknesses in rocks

Weaknesses include cracks, faults, and surfaces between layered rocks

Vein minerals fill in empty spaces after rocks collapse

Ex: Sphalerite Importance source of zinc-used in batteries

Titanium is a durable, lightweight, metallic element

Comes from minerals that have it Sources of titanium are ilmenite and

rutile Common in rocks that form when

magma cools and soldifies Titanium used to make cars, eyeglass

frames, golf clubs, bicycles, hip replacement