A++ mission 6 notes part ii 2012

Mission 6 Part IIMinerals

Minerals (ch. 3-1)

A. Five characteristics of minerals

1. Formed by natural processes

2. Inorganic

3. All solids4. Every mineral has a chemical composition unique to that mineral 

5. Atoms in a mineral are arranged in a

pattern repeated over and over

B. Structure of Minerals  1. Crystal: solid in which the atoms are arranged in a repeating pattern

2. 6 major crystal systems – Cubic, Orthorhombic, Tetragonal, Triclinic, Hexagonal, Monoclinic

C. How minerals form  1. Cooling of hot melted rock called magma a. As magma cools

atoms lose energy b. This causes them to

move closer together

c. atoms combine to form compounds

d. molecules of different compounds arrange

themselves in

repeating patterns

e. type and amount of elements present in

magma determine which elements will form

magma cools quickly = small crystals form

magma cools slowly = large crystals form

2. crystals can form from minerals dissolved in liquid

(crystals from solution)

a. liquid evaporates, atoms in mineral

stay behind and form crystals

D. Mineral composition and groups 1. 90 elements occur

naturally in earth’s crust

2. 98% of the crust is made up of only

8 elements

3. Silicates a. minerals that

contain silicone &

oxygen & one or more other minerals

b. silicon & oxygen are two most abundant

elements in the earth’s crust

Review• What five conditions must be meet for a

substance to be a mineral?

1. Formed by natural processes

2. Inorganic

3. All solids

4. Every mineral has a chemical composition unique to that mineral 

5. Atoms in a mineral are arranged in a pattern repeated over and over

II. Mineral Identification (Ch. 3-

2) 1. Physical properties: those that do not affect how it will react with other elements or compounds

1. Hardness a. how easily a

mineral can be scratched

b. diamond = hardest; talc = softest

a. Mohs scale of hardness

i. Used to compare the hardness of minerals

ii. lists the hardness of 10 minerals

2. Luster describes how light is reflected from a minerals surface

a. luster defined as metallic

i. always shines like metal

ii. very shiny

a. luster defined as nonmetallic

i. dull, glassy, pearly, silky

3. Color - a visual attribute of things that results from the light they emit or transmit or reflect; "a white color is made up of many different wavelengths of light"

4. Streak a. color of the mineral

when its broken up and powdered

b. strike plate (unglazed porcelain) mineral

rubbed across & streak is powdered mineral

c. only works when mineral is softer

than the strike plate

i. mineral graphite used in pencils because it leaves a streak on

paper          

5. Cleavage a. minerals that break

along smooth, flat surfaces

i. Example - mica

Mica

6. Fracture a. minerals that break

with rough, ragged edges

i. Example - quartz

Quartz

7. Other properties a. magnetism b. light (translucent)

Review• What’s the difference between a mineral

that has cleavage and one that has fracture?

Fracture - minerals that break with rough,

ragged edges

Cleavage -minerals that break along smooth,

flat surfaces

III. Uses of Minerals (Ch. 3-3)

A. Gems: highly prized minerals because

they are rare and beautiful

1. the difference between a gem and the common form of the same mineral

can be slight

i. Example – amethyst is a gem form of quartz

amethyst

B. Ores: mineral that contains a useful substance that can be mined at a profit

1. aluminum taken from bauxite and made into useful products

2. most ores contain unwanted material along with valuable material

i. this waste must be removed

ii. if this process is more costly than the value of the desired material, it will no

longer be classified an ore

Review

• Why couldn’t a company stay in business if the mineral it was mining were no longer an ore?

IV.Uses of Titanium (Ch.3-4)

A. Titanium is a durable, lightweight metal derived from minerals such as ilmenite or rutile

B. Used in things such as aircraft and cars

Review• Which two minerals are ores of titanium?

Ilmenite

Rutile