Building a House Out of Minerals

A roof is a barrier to snowand rain. What mineral is used in clay singles to cover the plywood sheets on the roof?

___________________

Cement is used for the foundation and chimneyof a house. Cement contains this mineralwhich is a source of calcium.

___________________

Exterior walls can be made of things such as aluminum or steel siding or brick. What is one mineral that could be found in aluminum siding? ___________________

Windows let in visible light and allow us to see outside. What clear mineral is used to make window glass? ___________________Electrical wiring conducts electricity

most wiring in made of metal. What mineral is often used for wiring? ___________________

Metal pipes are commonly used to carry fresh water into the house. In the 1950’s a poisonous mineral was used in plumbing, what was it? ___________________

Interior walls shape the rooms in a house. The wallboard covers the walls and is soft so that holes can be drilled in it for outlets and nails can be used to hang pictures. What mineral is wallboard made of? ___________________

Word Bank: Aluminum, Lead, Gypsum, Copper, Quartz, Illite (clay), Calcite

The Star of Bombay

182-carat star sapphire

Minerals versus Rocks

Composition and Structure of Minerals

Properties of Minerals

Mineral Groups

Mineral Resources

Minerals Versus RocksMinerals Versus Rocks

• A rock is an aggregate of minerals

• Minerals are the building blocks that make up rocks

Varieties of MineralsVarieties of Minerals

Quartz Olivine (Peridot)

Beryl (aquamarine) Native Copper

More than

3000

different

minerals

Definition of MineralDefinition of Mineral• Naturally occurring• Solid• Inorganic (never living)• Definite chemical composition• Orderly internal structure of atoms

Cubic

Tetragonal

Hexagonal

Chemical Chemical formula:formula:

CCChemical formula:

C

Graphite Diamond

How can 2 minerals with the same composition be so different?

What’s the point here?

“Internal Arrangement of Atoms” controls most physical properties!

Mineral FormationMineral Formation

1. Cooling of magma-molten rock beneath the earth’s surface

– if it cools fast small crystals– if it cools slowly large crystals

2. Compounds dissolved in a liquid (water); liquid evaporates & leaves behind crystals

• Most minerals made up of only 8 elements these 8 elements make up 98% of Earth’s crust

Relative abundance of the most common elements in the Earth’s crust

Element Approximate Percentage by Weight

Oxygen (O) 46.6%

Silicon (Si) 27.7%

Aluminum (Al) 8.1%

Iron (Fe) 5.0%

Calcium (Ca) 3.6%

Sodium (Na) 2.8%

Potassium (K) 2.6%

Magnesium (Mg) 2.1%

All Others 1.7%Total 100%

Mineral GroupsMineral Groups– Silicates: contains silicon + oxygen + one or

more other elements (Most common rock forming minerals are silicates)

– Carbonates: 1 carbon + 3 oxygen + other elements

– Oxides: 2 oxygen + other elements– Sulfides: sulfur + other elements– Sulfates: 1 sulfur + 4 oxygen + other elements– Halides: chlorine, fluorine, bromine, or Iodine

+ other elements– Native elements: elements that are

uncombined

QuartzQuartz Mica

KAl2(AlSi3O10)(OH,F,Cl)2SiO2

Can you find the “silica” ?

Silicates

Silica StructureSilica Structure

4 oxygen atoms for every 1 silicon atom

CalciteCalcite

Carbonates

Mineral IdentificationMineral Identification

• Hardness

• Color

• Streak Test

• Luster

• Crystal Form

• Cleavage / Fracture

Mineral PropertiesMineral PropertiesHardness - A measure of the resistance of a mineral to abrasion or scratching.

Mohs Hardness ScaleMohs Hardness Scale

Relative Scale Mineral Other ObjectsHardest 10 Diamond

9 Corundum

8 Topaz

7 Quartz

6 K-Feldspar 5.5 Glass, Pocketknife

5 Apatite

4 Fluorite 3.5 Copper Penny

3 Calcite 2.5 Fingernail

2 Gypsum

Softest 1 Talc

Colorless quartz Purple quartz (amethyst)

Brueno Jasper

Mineral PropertiesMineral Properties ColorColor

Mineral PropertiesMineral PropertiesStreak – The color of a mineral in its

powdered form.

The Mineral Hematite Always Has a Red Brown Streak Whether It Is the Metallic or Earthy Variety.

Mineral PropertiesMineral PropertiesLuster – the

appearance or quality of light

reflected from the surface of the

mineral.

• Metallic vs. nonmetallic

• Nonmetallic – vitreous (glassy), pearly, silky,

resinous, and earthy

Amethyst with vitreous luster

Mineral PropertiesMineral PropertiesCrystal form – the

external expression of a mineral’s internal orderly

arrangement of atoms.

Pyrite – Cubic Crystals

Quartz -Hexagonal Quartz -Hexagonal CrystalsCrystals

Quartz -Hexagonal Quartz -Hexagonal CrystalsCrystals

Mineral PropertiesMineral Properties

Cleavage – The tendency of a mineral

to cleave, or break, along planes of weak

bonding.

Simple cleavage in micasMultiple cleavages in

fluorite, halite and calcite

Halite

Fluorite

Calcite

1 plane - Micas2 planes – K Feldspar

3 planes – Halite (salt) 3 planes (rhombo.) - Calcite

Mineral PropertiesMineral Properties

Fracture-Minerals that do not break

along cleavage

planes are said to possess fracture

Conchoidal fracture in quartz

Mineral PropertiesMineral Properties

Specific gravity – compares the

weight of a mineral to the

weight of an equal volume of water.

High specific gravity of galena.

Additional PropertiesAdditional Properties• Effervescence - Calcite and powdered dolomite will

effervesce (fizz) in dilute hydrochloric acid (HCl) • Smell- Sphalerite will give off a rotten-egg smell when

streaked on a streak plate. (Note: pure sulfur does not smell like rotten eggs!)

• Magnetism- Magnetite (AKA Lodestone) will pick up paper clips (weak samples will only be able to pick up staples)

• Taste- Halite is rock salt and will taste salty. *Do not taste the samples since some have been tested with acid to see if it is calcite.

• Fluorescence- some minerals (mostly forms of calcite) will glow in fluorescent colors under a black (UV) light.

• Double refraction- some clear forms of calcite (Iceland Spar) will make a double image of words.

Additional PropertiesAdditional Properties

Fluorescence Double refraction

Uses of MineralsUses of Minerals

• Gems: highly prized minerals because they are rare and beautiful– Most gems are brighter and

more colorful than common samples of minerals

– Ex: Emeralds, rubies, diamonds

– Ex. Amethyst: a form of quartz with traces of iron, sapphires

– Trace amounts of elements can make some gems more rare than others = More money

Uses of MineralsUses of Minerals

• Ores: a mineral is an ore if it contains a useful substance that can be mined for a profit– Ex. Al from bauxite– Fe from hematite– Titanium from rutile

AsbestosAsbestos

• A mineral with threadlike, flexible fibers– Used for insulation and fire

protection = doesn’t burn or conduct heat

– When these fibers become loose and airborne → often get into the lungs where they’ve been known to cause cancer (carcinogen)