Minerals: Building Blocks of Rocks ~Chapter 5 ~ ^_^

Minerals: the building blocks of rocks  Definition of a mineral NaturalNatural InorganicInorganic SolidSolid Possess an orderly internal structure of atomsPossess an orderly internal structure of atoms Have a definite chemical compositionHave a definite chemical composition

Composition and structure of minerals  Atoms Smallest particles of matterSmallest particles of matter ElementsElements Basic building blocks of mineralsBasic building blocks of minerals Over 100 are knownOver 100 are known

Periodic table of the Elements Periodic table of the Elements

How atoms are constructed  Nucleus – central part of an atom that contains Protons – positive electrical chargesProtons – positive electrical charges Neutrons – neutral electrical chargesNeutrons – neutral electrical charges Have all the characteristics of an elementsHave all the characteristics of an elements  Energy levels, or shells Surround nucleusSurround nucleus Contain electrons – negative electrical chargesContain electrons – negative electrical charges

Simplified view of the atom

How atoms are constructed  Atomic number is the number of protons in an atom's nucleus  Bonding of atoms Forms a compound with two or more elementsForms a compound with two or more elements Ions are atoms that gain or lose electronsIons are atoms that gain or lose electrons  Isotopes Have varying number of neutronsHave varying number of neutrons

How atoms are constructed  Isotopes Have different mass numbers – the sum of the neutrons plus protonsHave different mass numbers – the sum of the neutrons plus protons Many isotopes are radioactive and emit energy and particlesMany isotopes are radioactive and emit energy and particles

Minerals  Physical properties of minerals  Crystal form  Luster  Color  Streak  Hardness  Cleavage  Fracture  Other properties (taste, smell, elasticity, malleability, feel, magnetism, double refraction)

Crystal Form

Luster

Cleavage

Streak

Hardness

Cleavage

Fracture

Other PropertiesCrystal Form

The mineral quartz often exhibits good crystal form

Pyrite (fool’s gold) displays metallic luster

Three examples of perfect cleavage – fluorite, halite, and calcite

Conchoidal fracture

Minerals  Physical properties of minerals Other propertiesOther properties FeelFeel MagnetismMagnetism Double RefractionDouble Refraction Reaction to hydrochloric acidReaction to hydrochloric acid

Minerals  A few dozen minerals are called the rock- forming minerals The eight elements that compose most rock- forming minerals are oxygen (O), silicon (Si), aluminum (Al), iron (Fe), calcium (Ca), sodium (Na), potassium (K), and magnesium (Mg)The eight elements that compose most rock- forming minerals are oxygen (O), silicon (Si), aluminum (Al), iron (Fe), calcium (Ca), sodium (Na), potassium (K), and magnesium (Mg) Most abundant atoms in Earth's crust:Most abundant atoms in Earth's crust: Oxygen (46.6% by weight)Oxygen (46.6% by weight) S ilicon (27.7% by weight)S ilicon (27.7% by weight)

Minerals  Major Mineral groups Rock-forming silicatesRock-forming silicates Most common mineral groupMost common mineral group Contain the silicon-oxygen tetrahedronContain the silicon-oxygen tetrahedron Four oxygen atoms surrounding a much smaller silicon atomFour oxygen atoms surrounding a much smaller silicon atom Feldspars are the most plentiful mineral groupFeldspars are the most plentiful mineral group Crystallize from molten materialCrystallize from molten material

Minerals  Mineral groups Rock-forming silicates :Rock-forming silicates : Olivine – independent tetrahedraOlivine – independent tetrahedra Pyroxene group – tetrahedra are arranged in chainsPyroxene group – tetrahedra are arranged in chains Amphibole group – tetrahedra are arranged in double chainsAmphibole group – tetrahedra are arranged in double chains

Hornblende – a member of the amphibole group Hornblende – a member of the amphibole group

Minerals  Mineral groups Rock-forming silicatesRock-forming silicates Micas – tetrahedra are arranged in sheetsMicas – tetrahedra are arranged in sheets Biotite and Muscovite Biotite and Muscovite Feldspars - BlockyFeldspars - Blocky Two types- Orthoclase and PlagioclaseTwo types- Orthoclase and Plagioclase Quartz –Quartz –

Potassium feldspar

Plagioclase feldspar Plagioclase feldspar

Major Mineral groups:  Nonsilicate Mineral Groups:  Oxides  Sulfides  Carbonates A major rock-forming groupA major rock-forming group Found in the rocks limestone and marbleFound in the rocks limestone and marble EvaporitesEvaporites Halite and gypsum are found in sedimentary rocksHalite and gypsum are found in sedimentary rocks Many have economic valueMany have economic value

Native Copper Native Copper

Some common non-silicate minerals

Mineral resources Reserves are already identified depositsReserves are already identified deposits Ores are useful metallic minerals that can be mined at a profitOres are useful metallic minerals that can be mined at a profit Economic factors may change and influence a resourceEconomic factors may change and influence a resource

An underground halite (salt) mine

The Bingham copper mine in Utah

Formative Mineral Quiz Directions:  Take out separate piece of paper and number 1-17  For each slide, identify the mineral either based on how it looks or on the clue given.  Correct quiz and record which ones you need study more! Directions:  Take out separate piece of paper and number 1-17  For each slide, identify the mineral either based on how it looks or on the clue given.  Correct quiz and record which ones you need study more!

Concoidal Fracture

IDENTIFY IT!

HCL Test (fizzing)

Double Refraction

IDENTIFY IT!

Perfect Cleavage (3 at 90 deg.)- NO THER HINTS!

Definitely not gold… unless you’re a fool.

Fibrous

MOHS = 1

Streak Test

Magnetic… but the streak is throwing me off

Uber Magnetic

Filmy… Flat… White…

Black. Black starts with B.

Metallic mineral. Ugly color.

Looks like Pyrite… but its not

Speckled. Reacts with Acid when powdered

Answer Key 1.Quartz (Box 1) 2.Olivine ( Box 1) 3.Calcite (Box 1) 4.Calcite (Box 1) 5.Azurite ( Box 2) 6.Halite (Box 3) 7.Pyrite ( Box 2) 8.Gypsum ( Box 1 OR 3) 9.Talc ( Box 3) 10.Hematite ( Box 2) 11.Hematite ( Box 2) 12.Magnetite ( Box 2) 13.Muscovite ( Box 1) 14.Biotite ( Box 1) 15.Limonite ( Box 2) 16.Chalcopyrite ( Box 2) 17.Dolomite ( Box 3) 1.Quartz (Box 1) 2.Olivine ( Box 1) 3.Calcite (Box 1) 4.Calcite (Box 1) 5.Azurite ( Box 2) 6.Halite (Box 3) 7.Pyrite ( Box 2) 8.Gypsum ( Box 1 OR 3) 9.Talc ( Box 3) 10.Hematite ( Box 2) 11.Hematite ( Box 2) 12.Magnetite ( Box 2) 13.Muscovite ( Box 1) 14.Biotite ( Box 1) 15.Limonite ( Box 2) 16.Chalcopyrite ( Box 2) 17.Dolomite ( Box 3)