Building a House Out of Minerals Cement is used for the foundation and chimney of a house. Cement contains this mineral which is a source of calcium. ___________________ A roof is a barrier to snow and rain. What mineral is used in clay singles to cover the plywood sheets on the roof? ___________________ 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? ___________________ 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? ___________________ Windows let in visible light and allow us to see outside. What clear mineral is used to make window glass? ___________________ 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? ___________________ Electrical wiring conducts electricity most wiring in made of metal. What mineral is often used for wiring? ___________________ Word Bank: Aluminum, Lead, Gypsum, Copper, Quartz, Illite (clay), Calcite

Composition and Structure of Minerals Properties of Minerals Minerals versus Rocks Composition and Structure of Minerals Properties of Minerals Mineral Groups Mineral Resources The Star of Bombay 182-carat star sapphire Minerals: Building Blocks of Rocks

Minerals Versus Rocks A rock is an aggregate of minerals Minerals are the building blocks that make up rocks

Varieties of Minerals More than 3000 different minerals Quartz Olivine (Peridot) Beryl (aquamarine) Native Copper

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

Tetragonal Cubic Hexagonal

How can 2 minerals with the same composition be so different? Graphite Diamond Chemical formula: C Chemical formula: C How can 2 minerals with the same composition be so different?

“Internal Arrangement of Atoms” controls most physical properties! What’s the point here? “Internal Arrangement of Atoms” controls most physical properties!

Mineral Formation Cooling of magma-molten rock beneath the earth’s surface if it cools fast small crystals if it cools slowly large crystals 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 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

Silicates Mica Quartz Can you find the “silica” ? SiO2 KAl2(AlSi3O10)(OH,F,Cl)2 Can you find the “silica” ?

Silica Structure 4 oxygen atoms for every 1 silicon atom

Carbonates Calcite

Mineral Identification Hardness Color Streak Test Luster Crystal Form Cleavage / Fracture

Mineral Properties Hardness - A measure of the resistance of a mineral to abrasion or scratching.

Mohs Hardness Scale 10 9 8 7 6 5 4 3 2 1 Relative Scale Mineral Other Objects Hardest 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

Mineral Properties Color Colorless quartz Purple quartz (amethyst) Brueno Jasper

Streak – The color of a mineral in its powdered form. Mineral Properties Streak – 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.

Nonmetallic – vitreous (glassy), pearly, silky, resinous, and earthy Mineral Properties Luster – 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

Pyrite – Cubic Crystals Quartz -Hexagonal Crystals Mineral Properties Crystal form – the external expression of a mineral’s internal orderly arrangement of atoms. Pyrite – Cubic Crystals Quartz -Hexagonal Crystals

Multiple cleavages in fluorite, halite and calcite Mineral Properties Cleavage – The tendency of a mineral to cleave, or break, along planes of weak bonding. Halite Calcite Fluorite Multiple cleavages in fluorite, halite and calcite Simple cleavage in micas

1 plane - Micas 2 planes – K Feldspar 3 planes – Halite (salt) 3 planes (rhombo.) - Calcite

Mineral Properties Fracture-Minerals that do not break along cleavage planes are said to possess fracture Conchoidal fracture in quartz

Mineral Properties Specific gravity – compares the weight of a mineral to the weight of an equal volume of water. High specific gravity of galena.

Additional 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 Properties Fluorescence Double refraction

Uses 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 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

Asbestos 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)