Introduction to MineralsIntroduction to Minerals

ObjectivesObjectives

DefineDefine mineralmineral..

CompareCompare the two main groups of the two main groups of minerals.minerals.

IdentifyIdentify the six types of silicate crystalline the six types of silicate crystalline structures.structures.

DescribeDescribe three common nonsilicate three common nonsilicate crystalline structures.crystalline structures.

Introduction to MineralsIntroduction to Minerals

Why study mineralsWhy study minerals

Made and remade on Earth’s surface, Made and remade on Earth’s surface, oceans, and in the layers inside of Earth.oceans, and in the layers inside of Earth.

They give us insight into Earth’s historical They give us insight into Earth’s historical development and dynamics.development and dynamics.

Essential to industryEssential to industry– Iron, copper, aluminum and magnesiumIron, copper, aluminum and magnesium

Why study minerals?Why study minerals?

Important to economyImportant to economy– Cost of rare to find “gem quality” mineralsCost of rare to find “gem quality” minerals– High costHigh cost

Environmental ImpactsEnvironmental Impacts– Extraction of mineralsExtraction of minerals

MineralsMinerals

Seen in our daily lives.Seen in our daily lives.

Many of you have already used a mineral Many of you have already used a mineral today.today.– ToothpasteToothpaste

Mica – sparklesMica – sparkles

– CarCarHematite – iron ore – steel (skyscrapers also)Hematite – iron ore – steel (skyscrapers also)

– Makeup (especially shimmer and glitter)Makeup (especially shimmer and glitter)Mica and talcMica and talc

Rarity Rarity

Some minerals are rare and highly prized for Some minerals are rare and highly prized for their characteristics.their characteristics.– Gold – conductivity, resistance to corrosion, high Gold – conductivity, resistance to corrosion, high

luster.luster.– Diamonds – Beauty andDiamonds – Beauty and

hardnesshardness

Some minerals are verySome minerals are very

common.common.– Quartz - sandQuartz - sand

What is a mineral?What is a mineral?

Nutritionist – things to be eatenNutritionist – things to be eaten– Add plant and animal life processes.Add plant and animal life processes.

Jeweler – a stone to be cut or polished.Jeweler – a stone to be cut or polished.

Geologist – a naturally occurring, inorganic Geologist – a naturally occurring, inorganic compound with a fixed chemical compound with a fixed chemical composition and an orderly internal composition and an orderly internal arrangement of atoms (IAOA).arrangement of atoms (IAOA).

Characteristics of MineralsCharacteristics of Mineralsmineral mineral a natural, usually inorganic solid a natural, usually inorganic solid that has a characteristic chemical that has a characteristic chemical composition, an orderly internal structure, composition, an orderly internal structure, and a characteristic set of physical and a characteristic set of physical properties.properties.

To be a mineral, a substance must have To be a mineral, a substance must have four characteristics:four characteristics:

it must be inorganic—it cannot be made of or by it must be inorganic—it cannot be made of or by living things;living things;it must occur naturally—it cannot be man-made;it must occur naturally—it cannot be man-made;it must be a crystalline solid;it must be a crystalline solid;it must have a consistent chemical composition.it must have a consistent chemical composition.

Characteristics of MineralsCharacteristics of Minerals

You can tell whether an object is a mineral by asking four questions.

Is it a nonliving material?

Is it a solid?

Does it have a crystalline structure?

Is it formed in nature?

Characteristics of Minerals, Characteristics of Minerals, continuedcontinued

The diagram below shows the four characteristics of minerals.

Crystalline StructureCrystalline Structure

Each type of mineral is characterized by a Each type of mineral is characterized by a specific geometric arrangement of atoms, or its specific geometric arrangement of atoms, or its crystalline structurecrystalline structure..

crystal crystal a solid whose atoms, ions, or molecules a solid whose atoms, ions, or molecules are arranged in a regular, repeating patternare arranged in a regular, repeating pattern

One way that scientists study the structure of One way that scientists study the structure of crystals is by using X rays. X rays that pass crystals is by using X rays. X rays that pass through a crystal and strike a photographic plate through a crystal and strike a photographic plate produce an image that shows the geometric produce an image that shows the geometric arrangement of the atoms in the crystal.arrangement of the atoms in the crystal.

How is a crystals shape How is a crystals shape determined?determined?

– Internal arrangement of atoms.Internal arrangement of atoms.– The arrangement of atoms is determined by The arrangement of atoms is determined by

the atoms of the minerals.the atoms of the minerals.– DEFINITE CRYSTAL STRUCTURE!DEFINITE CRYSTAL STRUCTURE!– Minerals can be grouped into Minerals can be grouped into crystal classes crystal classes

or systemsor systems..

Crystal SystemsCrystal Systems

Isometric – Cubic – look like blocksIsometric – Cubic – look like blocks– PyritePyrite

Tetragonal – 4 sided pyramids, prismsTetragonal – 4 sided pyramids, prisms– ZirconZircon

Hexagonal – 6 sided pyramids, prismsHexagonal – 6 sided pyramids, prisms– Beryl, quartzBeryl, quartz

Crystal SystemsCrystal Systems

Orthorhombic – short and stubbyOrthorhombic – short and stubby– TopazTopaz

Monoclinic – short and stubby with tilted Monoclinic – short and stubby with tilted faces at each end.faces at each end.– GypsumGypsum

Triclinic – sharp flat edges, no right anglesTriclinic – sharp flat edges, no right angles– FeldsparFeldspar

Mineral StructureTo understand what a crystalline structure is, you need to know a little about the elements that make up a mineral.

Elements are pure substances that cannot be separated or broken down into simpler substances by chemical means.– 92 different elements92 different elements– Represented by one or two letter symbolsRepresented by one or two letter symbols

O = OxygenO = OxygenSi = SiliconSi = Silicon

Atoms and Compounds

Atoms and Compounds Minerals may be either elements or compounds.

A compound is a substance made of atoms of two or more different elements joined by chemical bonds.

Example: Halite (NaCl)Example: Halite (NaCl)– Na is sodiumNa is sodium– Cl is chlorideCl is chloride

Kinds of MineralsKinds of Minerals

The 20 most common minerals are called The 20 most common minerals are called rock-forming rock-forming mineralsminerals because they form the rocks that make up because they form the rocks that make up Earth’s crust. Earth’s crust.

Ten minerals are so common that they make up 90% of Ten minerals are so common that they make up 90% of Earth’s crust. These minerals are quartz, orthoclase, Earth’s crust. These minerals are quartz, orthoclase, plagioclase, muscovite, biotite, calcite, dolomite, halite, plagioclase, muscovite, biotite, calcite, dolomite, halite, gypsum, and ferromagnesian minerals.gypsum, and ferromagnesian minerals.

All minerals can be classified into two main groups— All minerals can be classified into two main groups— silicate minerals and nonsilicate mineralssilicate minerals and nonsilicate minerals —based on —based on their chemical compositions.their chemical compositions.

Kinds of Minerals, Kinds of Minerals, continuedcontinuedSilicate MineralsSilicate Minerals

silicate mineralsilicate mineral a mineral that a mineral that contains a combination of contains a combination of Silicon (Si) and Oxygen (O)Silicon (Si) and Oxygen (O) and that may also contain and that may also contain one or more metals.one or more metals.

Common silicate minerals include:Common silicate minerals include:– quartz: the basic building block of many rocksquartz: the basic building block of many rocks– Feldspars: minerals that are the main component of most rocks on Feldspars: minerals that are the main component of most rocks on

Earth’s surfaceEarth’s surface– Micas: minerals that separate easily into sheets when they breakMicas: minerals that separate easily into sheets when they break– ferromagnesian minerals, such as amphiboles, pyroxenes, and ferromagnesian minerals, such as amphiboles, pyroxenes, and

olivines.olivines.

Silicate minerals make up 96% of Earth’s crust. Quartz and Silicate minerals make up 96% of Earth’s crust. Quartz and feldspar alone make up more than 50% of the crust.feldspar alone make up more than 50% of the crust.

Crystalline Structure is made up of some arrangement of:Crystalline Structure is made up of some arrangement of:– 4 oxygen atoms4 oxygen atoms– 1 silicon atom1 silicon atom

Silicate MineralsSilicate Minerals

Crystal Structure yields a silicon oxygen – Crystal Structure yields a silicon oxygen – tetrahedron.tetrahedron.

Kinds of Minerals, Kinds of Minerals, continuedcontinued

Nonsilicate MineralsNonsilicate Minerals

nonsilicate mineralnonsilicate mineral a mineral that a mineral that does not contain does not contain compounds of silicon and oxygencompounds of silicon and oxygen

Nonsilicate minerals comprise about 4% of Earth’s crust.Nonsilicate minerals comprise about 4% of Earth’s crust.

Nonsilicate minerals are organized into six major groups Nonsilicate minerals are organized into six major groups based on their chemical compositions.based on their chemical compositions.

The six major groups of nonsilicate minerals are The six major groups of nonsilicate minerals are carbonates, halides, native elements, oxides, sulfates, carbonates, halides, native elements, oxides, sulfates, and sulfides.and sulfides.

Classes of Nonsilicate MineralsA mineral that is composed of only one element is called a native element.

Gold and silver are examples of native elements

Made up of only ONE element – other examples of Made up of only ONE element – other examples of native elements are:native elements are:– Copper – CuCopper – Cu

– Iron – FeIron – Fe– Diamond – CDiamond – C

Native elements are used in communications and Native elements are used in communications and electronics equipmentelectronics equipment

Classes of Nonsilicate Minerals

CarbonatesCarbonates are minerals that contain are minerals that contain combinations of combinations of carbon and oxygencarbon and oxygen in in their chemical structuretheir chemical structure

Calcite and Dolomite Calcite and Dolomite are examples of Carbonates

Used in cement, building stones, and Used in cement, building stones, and fireworks.fireworks.

Classes of Nonsilicate Minerals

HalidesHalides are compounds that form when fluorine, are compounds that form when fluorine, chlorine, iodine, or bromine combine with chlorine, iodine, or bromine combine with sodium, potassium, or calcium.sodium, potassium, or calcium.

Fluorite and Halite Fluorite and Halite are examples of Halides

Halide minerals are used in the chemical Halide minerals are used in the chemical industry and in detergents.industry and in detergents.

Classes of Nonsilicate Minerals

OxidesOxides are compounds that form when an are compounds that form when an element, such as aluminum or iron, element, such as aluminum or iron, combines chemically with oxygen.combines chemically with oxygen.

CorundumCorundum is an exampleof an Oxide.

Oxide minerals are used to make Oxide minerals are used to make abrasives, aircraft parts, and paint.abrasives, aircraft parts, and paint.

Classes of Nonsilicate Minerals

Sulfates Sulfates are minerals that contain sulfur are minerals that contain sulfur and oxygen, SOand oxygen, SO44 . .

Gypsum/Selenite is an example of a Gypsum/Selenite is an example of a SulfateSulfate

Sulfates are used in cosmetics, Sulfates are used in cosmetics, toothpaste, cement, and pain.toothpaste, cement, and pain.

Classes of Nonsilicate Minerals

Sulfides Sulfides are minerals that contain one or more are minerals that contain one or more elements such as lead, iron, or nickel, combined elements such as lead, iron, or nickel, combined with sulfur. with sulfur.

Galena is an example of a Galena is an example of a Sulfide.Sulfide.

Sulfide minerals are used to Sulfide minerals are used to

make batteries, medicines, and electronic parts.make batteries, medicines, and electronic parts.

Reading CheckReading Check

What compound of elements will you never What compound of elements will you never find in a nonsilicate mineral?find in a nonsilicate mineral?

Nonsilicate minerals never contain Nonsilicate minerals never contain compounds of silicon bonded to oxygen.compounds of silicon bonded to oxygen.