Chapter 4: Section1Chapter 4: Section1What Are Minerals?What Are Minerals?

Minerals – a Minerals – a naturally naturally occurring, occurring, inorganicinorganic solid solid that has a that has a crystalcrystal structure and a structure and a definite definite chemicalchemical compositioncomposition

What 5 Characteristics What 5 Characteristics Does a Mineral Have to Does a Mineral Have to

Have?Have?A mineral must be:A mineral must be: Naturally OccurringNaturally Occurring InorganicInorganic SolidSolid Crystal StructureCrystal Structure Definite Chemical Definite Chemical CompositionComposition

What Does It Mean to Be What Does It Mean to Be Naturally Occurring?Naturally Occurring?

A mineral must occurA mineral must occur naturallynaturally

Cement, brick, Cement, brick, steel, and glass all steel, and glass all come from substances come from substances found in Earth’s found in Earth’s crustcrust but they are but they are manufacturedmanufactured by by peoplepeople

How Can Something Be How Can Something Be Inorganic?Inorganic?

InorganicInorganic – the – the mineral mineral cannotcannot arise arise from materials that from materials that were once part of a were once part of a livingliving thing thing

Ex. Ex. CoalCoal is is NOTNOT a a mineral because it is mineral because it is made up the made up the remainsremains of plants and animalsof plants and animals

What kind of pattern What kind of pattern must a mineral have?must a mineral have?

A mineral must have a A mineral must have a crystalcrystal structure – a structure – a repeatingrepeating pattern of pattern of a mineral’s particles a mineral’s particles that forms a that forms a solidsolid. .

FacesFaces – a crystal’s – a crystal’s flatflat side that meets side that meets at at sharpsharp edges and edges and cornerscorners

What kind of What kind of composition must a composition must a

mineral have?mineral have?A mineral must A mineral must have a definite have a definite chemicalchemical composition – it composition – it always contains always contains certain certain elementselements in definite in definite proportions; most proportions; most minerals are minerals are compoundscompounds

Cinnabar – composed of the elements Mercury and

Sulfur

What Is the Difference Between What Is the Difference Between an Element and a Compound?an Element and a Compound?

Element – a substance Element – a substance composed of acomposed of a singlesingle kind kind

ofof atomatom. . Ex. HydrogenEx. Hydrogen Compound –Compound – TwoTwo or moreor more elementselements combinedcombined so that so that the elements no longer have the elements no longer have distinctdistinct propertiesproperties Ex. Ex. Water HWater H2200

How Do You Identify How Do You Identify Minerals?Minerals?

Properties:Properties:DensityDensityCrystal Crystal ShapeShape

Cleavage and Cleavage and FractureFracture

Special Special PropertiesProperties

HardnessHardnessColor Color (this can (this can vary)vary)

StreakStreakLusterLuster

How Do You Determine a How Do You Determine a Mineral’s Hardness?Mineral’s Hardness?

Friedrich Mohs invented Friedrich Mohs invented a test to describe and a test to describe and compare the compare the hardnesshardness of of mineralsminerals

Mohs Hardness ScaleMohs Hardness ScaleRanks Ranks tenten minerals minerals from from softestsoftest to to hardesthardest

How Does the Mohs Scale How Does the Mohs Scale Work?Work?

Gypsum (2) will Gypsum (2) will scratchscratch talc (1), talc (1), calcite (3) will calcite (3) will scratchscratch gypsum gypsum (2), fluorite (4) (2), fluorite (4) will scratch will scratch calcite (3), etc.calcite (3), etc.

What Is a Streak Test?What Is a Streak Test?The streak of a The streak of a mineralmineral is the is the colorcolor of its of its powderpowder

The streak color and The streak color and the mineral color the mineral color are often are often differentdifferent

To test: rub a To test: rub a mineral against an mineral against an unglazed unglazed tiletile ((streakstreak plate) plate)

What is the Luster of a What is the Luster of a mineral?mineral?

Luster – used to Luster – used to describe how a mineraldescribe how a mineral reflectsreflects lightlight from from itsits surfacesurface

Minerals containing Minerals containing metals are oftenmetals are often shinyshiny

EarthyEarthy, waxy, and , waxy, and pearlypearly

What does Density have to What does Density have to do with Minerals?do with Minerals?

Each mineral has a Each mineral has a characteristiccharacteristic DensityDensity

Density – or mass per unit Density – or mass per unit volume; Density = volume; Density = mass/volumemass/volume

Displacement – the Displacement – the volumevolume of of the the displaceddisplaced water equals water equals the volume of the the samplethe volume of the the sample

What Kind of Shape does What Kind of Shape does a Mineral have?a Mineral have?

Minerals have a crystal Minerals have a crystal structurestructureCubicCubicHexagonalHexagonalTetragonalTetragonalOrthorhombicOrthorhombicMonoclinicMonoclinicTriclinicTriclinic

What is Mineral What is Mineral Cleavage?Cleavage? Cleavage – A Cleavage – A

mineral’s ability mineral’s ability to to splitsplit easily easily along a along a flatflat surfacesurface

The ability to The ability to breakbreak apart apart depends on the depends on the arrangement of the arrangement of the atomsatoms in the in the mineralmineral

Cubic Cleavage

Basal Cleavage

What is Mineral What is Mineral Fracture?Fracture?

Fracture – How a Fracture – How a mineral mineral lookslooks when it when it breaks breaks apartapart in an in an irregular wayirregular way

What Special Properties What Special Properties does a Mineral have?does a Mineral have?

Fluorescence –minerals that Fluorescence –minerals that glowglow under ultraviolet light under ultraviolet light

Magnetism - ex. LoadstoneMagnetism - ex. LoadstoneChemical Reactivity- ex. Chemical Reactivity- ex. Calcite gives off Calcite gives off carboncarbon dioxidedioxide

ElectricalElectrical Properties – ex. Properties – ex. quartzquartz

Section2: Section2: How are Minerals Formed?How are Minerals Formed?

Two General Ways:Crystallization of melted materialsMinerals from Magma

Crystallization of materials dissolved in waterMinerals from Hot water solutions

Minerals formed by evaporation

What is What is Crystallization?Crystallization?

Crystallization Crystallization the the processprocess by which by which atoms are atoms are arrangedarranged to to form a material with a form a material with a crystalcrystal structure structure

How do Minerals form from How do Minerals form from Magma?Magma?

Minerals form as Minerals form as magmamagma cools inside the cools inside the crustcrust, or as , or as lavalava hardens on the surfacehardens on the surface

What Effects Crystal What Effects Crystal Size?Size?RateRate at which magma at which magma

coolscoolsSlower Slower coolingcooling forms forms larger crystalslarger crystals

The amount of The amount of gasgas the the magma containsmagma contains

The The chemicalchemical composition composition of the magmaof the magma

How do Minerals Form from How do Minerals Form from Hot Water Solutions?Hot Water Solutions?

MagmaMagma beneath Earth’s beneath Earth’s surface has heated the surface has heated the water to a high water to a high temperature beneath temperature beneath Earth’s surface causing Earth’s surface causing minerals to minerals to dissolvedissolve

When this solution When this solution coolscools the the elementselements and compounds and compounds leave the solution and leave the solution and crystallizecrystallize as minerals as minerals

What is a Solution?What is a Solution?

Solution – A Solution – A mixturemixture in which one substance in which one substance dissolvesdissolves in in anotheranother

What do Pure Metals often What do Pure Metals often form from Hot Water form from Hot Water

Solutions?Solutions? Veins – A narrow channel orVeins – A narrow channel or slabslab of aof a mineralmineral that is that is much different from the much different from the surrounding rocksurrounding rock

How are Minerals Formed by How are Minerals Formed by Evaporation?Evaporation?

As water turns to As water turns to vaporvapor it leaves behind the it leaves behind the mineralmineral

Example: A salt water Example: A salt water solution leaves behind solution leaves behind large crystals of large crystals of saltsalt

Where are Minerals Where are Minerals Found?Found?

Earth’s crust is made up of a Earth’s crust is made up of a variety of minerals however; variety of minerals however; rarerare and less common minerals and less common minerals are usually located near are usually located near plateplate boundariesboundaries because of because of volcanicvolcanic activity and activity and mountain buildingmountain building

Section 3: How are Section 3: How are Minerals Used?Minerals Used?

Minerals are the source ofMinerals are the source ofMetalsMetals ex. Aluminum, Iron ex. Aluminum, IronGemstonesGemstones ex. Rubies and ex. Rubies and SapphiresSapphires

Other Useful materials Other Useful materials ex. ex. TalcTalc (talcum powder) (talcum powder)

Ore What?Ore What?

Ore - A Ore - A rockrock that contains that contains a a metalmetal or economically or economically useful mineraluseful mineral

Most metals, gemstones, and Most metals, gemstones, and useful minerals must be useful minerals must be separatedseparated from their ores from their ores

What are the 3 Types of What are the 3 Types of Mines?Mines?

StripStrip Mines – Giant Mines – Giant equipment is used to equipment is used to scrape away soilscrape away soil

OpenOpen PitPit Mines – Miners Mines – Miners dig a tremendous pitdig a tremendous pit

ShaftShaft Mines – A network Mines – A network of tunnels that extend of tunnels that extend deep undergrounddeep underground