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MineralsBuilding Blocks of Rocks
MineralsBuilding Blocks of Rocks
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Mastering Chapter 2 – You should know:Mastering Chapter 2 – You should know: What minerals are and how they areWhat minerals are and how they are different than rocks.different than rocks.
The basic structure of the atom andThe basic structure of the atom and how atoms are used to build mineralshow atoms are used to build minerals (bonding).(bonding).
How common elements in the earth’s crust make How common elements in the earth’s crust make up the various mineral families.up the various mineral families.
How to use mineral physical properties and How to use mineral physical properties and identify common rock-forming minerals.identify common rock-forming minerals.
The definition of a mineral resource and The definition of a mineral resource and understand the characteristics of ore deposits.understand the characteristics of ore deposits.
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What makes minerals and rocks ?What makes minerals and rocks ?
Fe, Mg, Si, O, K chemical compounds igneous, sedimentary, metamorphic
silicon (Si)silicon (Si)silicon (Si)silicon (Si)
oxygen (O)oxygen (O)
iron (Fe)iron (Fe)
quartzquartz
orthoclaseorthoclase
biotitebiotite
granitegranite
sandstonesandstone
gneissgneiss
ElementsElements MineralsMinerals RocksRocks
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The basic atom model (inside the atom)Protons Protons Electrons Electrons Neutrons Neutrons N
N
N
N
N
N N
e
ee
e
e
e e
electron shellselectron shells Atomic numberAtomic number• number of protonsnumber of protons• determines chemicaldetermines chemical characteristicscharacteristics• range from 1 (H) torange from 1 (H) to 92 (Ur)92 (Ur)+++
+++
+
Atomic massAtomic mass• protons + neutronsprotons + neutrons• neutrons add “atomicneutrons add “atomic weight”weight”• same atom can havesame atom can have varying number of varying number of neutrons-- isotopesneutrons-- isotopes
nucleusnucleus
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Germanium atoms (Gr)cobalt (Co) atoms bonding with copper (Cu) atomscobalt (Co) atoms bonding with copper (Cu) atoms
silicon + oxygensilicon + oxygen(silicate tetrahedron)(silicate tetrahedron)silicon + oxygensilicon + oxygen(silicate tetrahedron)(silicate tetrahedron)
Oxygen (4)Oxygen (4)Oxygen (4)Oxygen (4)
Silicon (1)Silicon (1)
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Elements and the Periodic Table (PT)Elements and the Periodic Table (PT)
ELEMENTSELEMENTS
• Considered a pure substanceConsidered a pure substance• each element has its own atomic numbereach element has its own atomic number
• About 118 known elements (92 natural, 26 synthetic)About 118 known elements (92 natural, 26 synthetic)
• Elements possess distinctive physical propertiesElements possess distinctive physical properties• hardness, boiling points hardness, boiling points • solid, liquid, or gassolid, liquid, or gas
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increasing atomic increasing atomic numbersnumbers
Groups similarproperties
Periods
Non-m
etals
Non-m
etals
Metalloids
Metalloids
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Interpreting the PT-Interpreting the PT-
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AuAu197.0197.0
GoldGold
Atomic numberAtomic number• number of protonsnumber of protons
Elemental symbolElemental symbol
Atomic weightAtomic weight• protons + neutronsprotons + neutrons
Element nameElement name
So, observing the PT patterns and the definition of an element,So, observing the PT patterns and the definition of an element, what characteristics distinguish one element from another?what characteristics distinguish one element from another?
Why is an element considered a pure substance????Why is an element considered a pure substance????
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I I I I Earth Science better the secondEarth Science better the second week. week.Earth Science better the secondEarth Science better the second week. week.
I will get an A on my exams and quizzes.I will get an A on my exams and quizzes.
Discuss with a friend:Discuss with a friend:
1.1.What are the parts of an atom? – beWhat are the parts of an atom? – be specific (sub-atomic parts).specific (sub-atomic parts).
2. How would you describe a chemical2. How would you describe a chemical element?element?
3. What distinguishes one element from3. What distinguishes one element from another?another?
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Bonding the atoms (elements)Bonding the atoms (elements)Bonding the atoms (elements)Bonding the atoms (elements)
Atoms bond using Atoms bond using electrons found at the electrons found at the most outer electron most outer electron energy shellenergy shell ( (valence valence shell)shell)
Atoms bond using Atoms bond using electrons found at the electrons found at the most outer electron most outer electron energy shellenergy shell ( (valence valence shell)shell)
Pe e
e
e
ee
e e
e e
eValence shellValence shellValence shellValence shell
Electrons enter higher shell levels afterElectrons enter higher shell levels afterlower shell levels have been filled.lower shell levels have been filled.
Electrons will either be Electrons will either be sharedshared or or transferredtransferred to other atoms to other atoms at at the the valence shell.valence shell.
The atom wants to be satisfied or The atom wants to be satisfied or stablestableby filling the electron shells to capacity.by filling the electron shells to capacity.Electrons are Electrons are lostlost OR OR gainedgained when whensatisfying the outer shell (valence shell).satisfying the outer shell (valence shell).
IonsIons – – the net electric charge of the atomthe net electric charge of the atom• loses an electron (positive charge)loses an electron (positive charge)• gains an electron (negative charge)gains an electron (negative charge)• equal number of electrons/protonsequal number of electrons/protons (electrically balanced – neutral)(electrically balanced – neutral)• Cation (+ ions), Anions (-) ionsCation (+ ions), Anions (-) ions
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Writing a chemical compoundWriting a chemical compound(Chemistry nomenclature) (Chemistry nomenclature)
Chemical compounds form when combining elementsChemical compounds form when combining elementsat a specific ratio (atom to atom)at a specific ratio (atom to atom)
• metals (cations) combine with non-metals (anions)metals (cations) combine with non-metals (anions)• Examples:Examples:
HH++ HH++OO-2-2
+ HH++22cationcation
OO-2-2anionanion
HH22OOcompoundcompound
Na ++ ClCl NaClNaClcationcation anionanion compoundcompound
MoleculeMolecule• smallestsmallest chemical unit formed by 2 or more atoms chemical unit formed by 2 or more atoms• held together by electromagnetic forces (bonds)held together by electromagnetic forces (bonds)• expresses properties of the compoundexpresses properties of the compound
waterwatermoleculemolecule
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Combining Elements (Atoms) to Make MineralsCombining Elements (Atoms) to Make Minerals
Elements are bonded through “electrical glue” using electronsElements are bonded through “electrical glue” using electronsfrom various element configurations that form chemical from various element configurations that form chemical compounds. Compounds display completely different physicalcompounds. Compounds display completely different physicalproperties.properties.
Example:Example:
+ + NaClNaClNaNa ClCl
• sodium (Na)sodium (Na)• metallicmetallic• softsoft• explosiveexplosive• lethal!lethal!
• chlorine (Cl)chlorine (Cl)• yellow gasyellow gas• lethal!lethal!
• halitehalite• new propertiesnew properties• compoundcompound• can eat itcan eat it• we need itwe need it
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Bonding the elementsBonding the elements – the force that holds the – the force that holds the atoms together in a chemical compoundatoms together in a chemical compound
Types of bonding (atomic bonds)Types of bonding (atomic bonds)
• Ionic bondingIonic bonding
• Covalent bondingCovalent bonding
• Metallic bondingMetallic bonding
• Van der Waals bondingVan der Waals bonding
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The Ionic BondThe Ionic Bond – – electrons electrically electrons electrically transferredtransferred
+NaNa
ee
= NaClNaCl
Sodium ion wants toSodium ion wants toloselose the electron the electron (+) positive charge ion(+) positive charge ion
Chlorine ion wants toChlorine ion wants togaingain the electron the electron(-) charged ion(-) charged ion
eeee
eeee
eeee
ClCl
ee
ee
The Ionic BondThe Ionic Bond• moderate strength and hardnessmoderate strength and hardness• weak bond (salt dissolves in water)weak bond (salt dissolves in water)
1 = valence shell1 = valence shell 7 = valence shell7 = valence shell
Mineral examplesMineral examples• halite (table salt)halite (table salt)• biotitebiotite
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Gain or shareelectrons at the valence shell
NaCl = Halite (Salt)NaCl = Halite (Salt)
Loses electrons at theLoses electrons at thevalence shellvalence shell(+) charged ions(+) charged ions
(-) charged ions
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The Covalent BondThe Covalent Bond – – sharing sharing electronselectrons
eeee
eeee
eeeeeeee cccceeee
eeee
eeee
eeee cccc
eeeeeeee
eeeeeeee
cccc
eeeeeeee
eeee eeee
cccc
eeeeeeee
eeee eeee
cccceeeeeeee
eeeeeeeecccc
The DiamondThe Diamond““perfect geometry”perfect geometry”
The Covalent BondThe Covalent Bond•the strongest bondthe strongest bond•most minerals will scratch glassmost minerals will scratch glass•extremely hard to break the bondsextremely hard to break the bonds
The Covalent BondThe Covalent Bond•the strongest bondthe strongest bond•most minerals will scratch glassmost minerals will scratch glass•extremely hard to break the bondsextremely hard to break the bonds
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Metallic bondingMetallic bonding – – tightly packed atoms “stick”tightly packed atoms “stick”to each other (a form of sharing). Outermost electronsto each other (a form of sharing). Outermost electrons(loosely held) freely move from one atom to the next.(loosely held) freely move from one atom to the next.
• good conductors of heat andgood conductors of heat and electricityelectricity
• heavy “dense”heavy “dense”
• malleable (metals bend easily)malleable (metals bend easily)
• polish easilypolish easily
Examples of metallic minerals:Examples of metallic minerals:
galena (PbS)galena (PbS) pyrite (Fepyrite (Fe22S)S) gold (Au)gold (Au) 1717
Van der Waals bondingVan der Waals bonding – – weak attraction betweenweak attraction betweenelectrically neutral molecules; (+) end of the moleculeelectrically neutral molecules; (+) end of the moleculeis attracted to the (-) end of the molecule.is attracted to the (-) end of the molecule.
Carbon atoms
Covalentbonds
Van derWaals bonds
• very weak bondsvery weak bonds
• easily brokeneasily broken
• “ “layers” slip past onelayers” slip past one anotheranother
Graphite exampleGraphite example
So, why do graphite and diamond displaydifferent physical properties (hardness???)—They are both composed of carbon. 1818
I I I I Earth Science. Earth Science. Earth Science. Earth Science.
I will get an A on my exams and quizzes.I will get an A on my exams and quizzes.
Discuss with a friend:Discuss with a friend:
1.1.What part of the atom bonds togetherWhat part of the atom bonds together to form compounds?to form compounds?
3. Explain the differences between 3. Explain the differences between ionicionic, , covalentcovalent, , metallicmetallic, and Van der, and Van der Waals bondsWaals bonds. .
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What objects below do you think are What objects below do you think are minerals??minerals??
GoldGold
GasolineGasoline
DiamondDiamond
WaterWater
WoodWood
What are Minerals?What are Minerals?
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Why are Why are goldgold, , pyritepyrite, , andand diamonddiamond considered minerals? considered minerals?
The 5-part mineral definition:The 5-part mineral definition:
• Naturally occurringNaturally occurring• Inorganic (non-living)Inorganic (non-living)• Homogeneous – solidHomogeneous – solid• Definite chemical compositionDefinite chemical composition• Definite crystalline internal structureDefinite crystalline internal structure
• 4,000 different minerals (fits 5-part 4,000 different minerals (fits 5-part definition)definition) • 25 common minerals combined to form 25 common minerals combined to form rocksrocks 2121
I I I I Earth Science. Earth Science. Earth Science. Earth Science.
I will get an A on my exams and quizzes.I will get an A on my exams and quizzes.
Discuss with a friend:Discuss with a friend:
1.1.What is the “5-part definition” of aWhat is the “5-part definition” of a mineral?mineral?
2. Name 3 substances that are NOT 2. Name 3 substances that are NOT minerals and 3 substances that areminerals and 3 substances that are minerals.minerals.3.3.Is ice a mineral? Is water a mineral?Is ice a mineral? Is water a mineral? why or why not?why or why not?
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Do all minerals possess a definite or specificDo all minerals possess a definite or specificchemical composition?chemical composition?Atomic substitutionAtomic substitution::
• Two elements can have similar sizes and be Two elements can have similar sizes and be substituted within a compound.substituted within a compound.
• Bonding properties are similar.Bonding properties are similar.
Example: the mineral Olivine series (FeExample: the mineral Olivine series (Fe2+2+, Mg, Mg2+2+))• Both ions are similar in size and charge.Both ions are similar in size and charge.• Ions exchange (in ratio) with each other within theIons exchange (in ratio) with each other within the crystal lattice.crystal lattice.
Olivine seriesOlivine series
FeFe22SiOSiO44 MgMg22SiOSiO44(Fe,Mg)(Fe,Mg)22SiOSiO44fayolitefayolite forsteriteforsterite
““olivine”olivine” 2323
What’s inside a mineralWhat’s inside a mineral
A mineral’s A mineral’s crystalline structurecrystalline structure (internal geometric shape) is the (internal geometric shape) is the result of the atomic arrangement of result of the atomic arrangement of atoms (how the atoms align).atoms (how the atoms align).
What’s inside a mineralWhat’s inside a mineral
A mineral’s A mineral’s crystalline structurecrystalline structure (internal geometric shape) is the (internal geometric shape) is the result of the atomic arrangement of result of the atomic arrangement of atoms (how the atoms align).atoms (how the atoms align).
Cl (Chlorine atom)Cl (Chlorine atom)Cl (Chlorine atom)Cl (Chlorine atom)
Na (Sodium atom)Na (Sodium atom)Na (Sodium atom)Na (Sodium atom)
Dependent on:Dependent on:• the size of various combining ionsthe size of various combining ions• how the ions bond togetherhow the ions bond together
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Do ALL minerals “grow” and show the observer their crystalline shape? (how the atoms combine)Do ALL minerals “grow” and show the observer their crystalline shape? (how the atoms combine)
Fe2SFe2S
PyritePyrite
QuartzQuartzSiO2SiO2
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Why do some minerals show their internal structure to the observer?Why do some minerals show their internal structure to the observer?
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large gypsum crystalsformed 150 feet below thesurface
large gypsum crystalsformed 150 feet below thesurface
Enough spaceEnough timeEnough solution
Enough spaceEnough timeEnough solution
Chihuahua Desert, MexicoChihuahua Desert, Mexico
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The atomic arrangement of atoms in a liquidThe atomic arrangement of atoms in a liquid• there is nonethere is none• atoms are randomly arrangedatoms are randomly arranged• an an amorphous solidamorphous solid
• a “liquid-type” solid possessing no internala “liquid-type” solid possessing no internal structurestructure• amorphous material has no melting pointamorphous material has no melting point• Example:Example: glass, plastic, waxglass, plastic, waxamorphousamorphous
structurestructure
crystallinecrystallinestructurestructure
WaxesWaxes
GlassGlassPlastic
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I I I I Earth Science better the secondEarth Science better the second week. week.Earth Science better the secondEarth Science better the second week. week.Discuss with a friend:Discuss with a friend:
1.1.What dictates a mineral’s crystallineWhat dictates a mineral’s crystalline structure?structure?
2. What conditions must be met to form2. What conditions must be met to form perfect crystal faces?perfect crystal faces?
3.3.Do all minerals show their crystallineDo all minerals show their crystalline structure to the observer (why/why not)?structure to the observer (why/why not)?
4. Describe the differences between 4. Describe the differences between amorphousamorphous and and crystallinecrystalline structures. structures.
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Mineral IdentificationMineral Identification• Minerals are properly identified using a combination of Minerals are properly identified using a combination of physical propertiesphysical properties that reflect the mineral’s crystalline that reflect the mineral’s crystalline structurestructure and and chemical compositionchemical composition..
Physical PropertiesPhysical Properties Used to Identify Minerals Used to Identify Minerals• luster – luster – how the mineral reflects lighthow the mineral reflects light• hardness – hardness – the resistance to scratchingthe resistance to scratching• crystal form – crystal form – angle between crystal facesangle between crystal faces• cleavage – cleavage – breaks along atomic planes of breaks along atomic planes of weaknessweakness• streak – streak – color of the powdered residue left on a color of the powdered residue left on a porcelain plateporcelain plate• color – color – most noticeable, least reliablemost noticeable, least reliable• density – “How heavy is the mineral for its size?”density – “How heavy is the mineral for its size?”
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Luster of the MineralHow the mineral reflects light – Is the mineral How the mineral reflects light – Is the mineral metallicmetallicor or non-metallic?non-metallic?
Metallic lusterMetallic luster – “shiny,” like polished metal – “shiny,” like polished metal
Non-metallic Non-metallic ((vitreousvitreous, , resinousresinous, , pearlypearly, , greasygreasy, , earthyearthy))
vitreousvitreous
““glassy”glassy”
resinousresinous
““tree sap”tree sap”
pearlypearly
pearlspearls
greasygreasy earthyearthy
chalkchalk
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Hardness of a MineralIs the mineral “soft” or “hard,” or how resistant is it to Is the mineral “soft” or “hard,” or how resistant is it to scratching?scratching?
• governed by the mineral’s crystal structure and governed by the mineral’s crystal structure and chemical bondschemical bonds• the stronger the bond, the harder the mineralthe stronger the bond, the harder the mineral
Relative hardness,not uniform
Mohs Hardness ScaleMohs Hardness Scale3232
Crystal facesCrystal faces – – any solid body that has grown withany solid body that has grown withflat “planar” surfaces called crystal facesflat “planar” surfaces called crystal faces
• The same mineral may grow in a large, small, The same mineral may grow in a large, small, or skinny form, but the or skinny form, but the ANGLEANGLE between crystal faces between crystal faces will always remain the same. will always remain the same.
• reflects the internal atomic arrangement of atomsreflects the internal atomic arrangement of atoms
• proved by Danish physician- Nicolaus Steno, 1669proved by Danish physician- Nicolaus Steno, 1669
• Steno’s Law states:Steno’s Law states:The angle between any correspondingThe angle between any corresponding
pairs of crystal faces of a given mineral ispairs of crystal faces of a given mineral is constant no matter what the overall shapeconstant no matter what the overall shape or size of the crystal might be.or size of the crystal might be.
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Examples of atom by atom crystal growthexhibiting various angles
fat, skinny, tall, short, etc… all the same anglesfat, skinny, tall, short, etc… all the same angles
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Cleavage Planes-Cleavage Planes- repeating smooth flat surfaces where repeating smooth flat surfaces where the mineral breaks along planes of atomic weaknessthe mineral breaks along planes of atomic weakness
• Once the mineral breaks, flat surfaces repeat the Once the mineral breaks, flat surfaces repeat the same angle on broken fragments.same angle on broken fragments.
• Cleavage angles are consistent. Cleavage angles are consistent. • Examples:Examples:
Cleavage Planes-Cleavage Planes- repeating smooth flat surfaces where repeating smooth flat surfaces where the mineral breaks along planes of atomic weaknessthe mineral breaks along planes of atomic weakness
• Once the mineral breaks, flat surfaces repeat the Once the mineral breaks, flat surfaces repeat the same angle on broken fragments.same angle on broken fragments.
• Cleavage angles are consistent. Cleavage angles are consistent. • Examples:Examples:
Mica minerals – have oneMica minerals – have oneperfect plane of cleavage,perfect plane of cleavage,““cleave” like book pagescleave” like book pages
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StreakStreak – – the color of the powder left on a porcelainthe color of the powder left on a porcelainplate (streak plate)plate (streak plate)
• The mineral is rubbed on a porcelain plate leaving The mineral is rubbed on a porcelain plate leaving a colored powder.a colored powder.
• The mineral color does not always give the same colorThe mineral color does not always give the same color of powdered residue on the porcelain plate.of powdered residue on the porcelain plate.
Mineral’s streakMineral’s streak The mineral’s streak is notThe mineral’s streak is notalways the same color as the always the same color as the mineral.mineral.
HematiteHematite 3636
Color – the appearance of the mineral, “What color arethese minerals?” 3737
DensityDensity-- “How heavy is the mineral?” “How heavy is the mineral?”
Which weighs more?- a pound of Which weighs more?- a pound of feathers feathers or a pound of or a pound of gold??gold??
• How much How much massmass can be packed in a given can be packed in a given volume?volume?• D = M/V, units of g/cmD = M/V, units of g/cm33
• high-density minerals = closely packed atomshigh-density minerals = closely packed atoms low-density minerals = less packed atomslow-density minerals = less packed atoms
Range of common mineral densities: 2.5 g/cmRange of common mineral densities: 2.5 g/cm33 – 3.0 g/cm – 3.0 g/cm33
Experience allows the earth scientist to just “lift” the Experience allows the earth scientist to just “lift” the mineral and determine if it is less or greater than the mineral and determine if it is less or greater than the density range for common minerals.density range for common minerals.
• metallic minerals feel heavy for their sizemetallic minerals feel heavy for their size• non-metallic (vitreous) minerals feel light for their non-metallic (vitreous) minerals feel light for their sizesize 3838
I I I I Earth Science better the secondEarth Science better the second week. week.Earth Science better the secondEarth Science better the second week. week.Discuss with a friend:Discuss with a friend:
1.1.Briefly describe the following mineralBriefly describe the following mineral physical properties:physical properties:
lusterluster cleavagecleavagehardnesshardness densitydensitycrystal formcrystal form colorcolorstreakstreak
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8 8 elements make up the rock forming elements make up the rock forming mineralsminerals
Oxygen (O) Oxygen (O) 45.20%45.20%Silicon (Si) Silicon (Si) 27.20%27.20%Aluminum (Al)Aluminum (Al) 8.00% 8.00%Iron (Fe)Iron (Fe) 5.80% 5.80%Calcium (Ca)Calcium (Ca) 5.06% 5.06%Magnesium (Mg)Magnesium (Mg) 2.77% 2.77%Sodium (Na)Sodium (Na) 2.32% 2.32%Potassium (K)Potassium (K) 1.68% 1.68%
OtherOther > 1% > 1% Ti, H, Mn, PTi, H, Mn, P
Mineral FamiliesMineral Families• Scientists have identified approx. 4,000 minerals.Scientists have identified approx. 4,000 minerals.• What’s in a rock? – common elements that make upWhat’s in a rock? – common elements that make up rocksrocks
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Minerals of the Earth’s CrustMinerals of the Earth’s Crust
Minerals are separated into mineral Minerals are separated into mineral classes.classes.
based on the anion complexbased on the anion complex metal (Cation) + non-metal (Anion)metal (Cation) + non-metal (Anion) Example: NaClExample: NaCl
The Mineral Groups according to the The Mineral Groups according to the anionanion
Oxides (0)Oxides (0) Sulfides (S)Sulfides (S) Sulfates (S0Sulfates (S044))Native ElementsNative Elements Halides (Group 17)Halides (Group 17) Carbonates (C0Carbonates (C033))Silicates (Si0Silicates (Si044))
CationCation AnionAnion
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What two elements combined would produce the What two elements combined would produce the mostmost
abundant mineral group?abundant mineral group?Si and 0Si and 0
Silicon and Oxygen combined make the Silicon and Oxygen combined make the Silicate mineral Silicate mineral group.group.
•Largest mineral groupLargest mineral group
•Si + 0 = (Si + 0 = (Si0Si044))4-4-
•Forms the Si0Forms the Si044 Tetrahedron Tetrahedron • covalently bondedcovalently bonded•4 oxygens with 1 silicon4 oxygens with 1 silicon•building block for all silicate mineralsbuilding block for all silicate minerals•very strong bond – hard to breakvery strong bond – hard to break•(Si0(Si044))-4-4 unstable, wants to combine with unstable, wants to combine with metalsmetals
“triangles” put together – very stablemakes tough, hard minerals 4242
I I I I Earth Science better the thirdEarth Science better the third week. week.Earth Science better the thirdEarth Science better the third week. week.
I will get an A on my exams and quizzes.I will get an A on my exams and quizzes.
Discuss with a friend:Discuss with a friend: 1. How are minerals grouped? Name1. How are minerals grouped? Name at least four groups.at least four groups.
2. Name the two most common elements2. Name the two most common elements comprising the rock forming minerals.comprising the rock forming minerals.
3.3.Describe the characteristics of the silicateDescribe the characteristics of the silicate tetrahedron.tetrahedron.
4. Why is the tetrahedron so strong?4. Why is the tetrahedron so strong?
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How the silicate tetrahedrons bond:How the silicate tetrahedrons bond:• silicate tetrahedron configurations are a function of temp.silicate tetrahedron configurations are a function of temp.• bonding of most silicates is a combination of bonding of most silicates is a combination of covalent and ionic bondscovalent and ionic bondsHotHot
CoolCool
Single tetrahedronSingle tetrahedronMgMg22SiOSiO44
OlivineOlivine
Silicate Silicate tetrahedrontetrahedron
Hexagonal ringHexagonal ringBeBe33AlAl22SiSi66OO1818BerylBeryl
Single chainSingle chainCa Mg (SiOCa Mg (SiO33))22PyroxenePyroxene
groupgroup Double chainDouble chainCaCa22MgMg55(Si(Si44OO1111))22(OH)(OH)22
AmphiboleAmphibolegroupgroup
MicaMicagroupgroup
SheetSheetK(MgFe)K(MgFe)33(AlSi(AlSi33OO1010)(OH))(OH)22
FrameworkFrameworktetrahedrontetrahedron
SiOSiO22
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Accessory MineralsAccessory Minerals – – less common minerals butless common minerals butwidely present in rocks in small concentrationswidely present in rocks in small concentrations
• Accessory minerals do not determine the propertiesAccessory minerals do not determine the properties of rocks.of rocks.• Some are economically important.Some are economically important.
• galena – PbS galena – PbS chalcopyrite – CuFeSchalcopyrite – CuFeS22
(lead ore)(lead ore) (copper ore)(copper ore)
Some minerals have the same composition butSome minerals have the same composition butdiffer in their atomic structure.differ in their atomic structure.
• PolymorphsPolymorphs• graphite and diamond (carbon)graphite and diamond (carbon)• calcite and aragonite (calcium carbonate)calcite and aragonite (calcium carbonate)• pyrite and marcasite (FeSpyrite and marcasite (FeS22- iron sulfide)- iron sulfide)
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What are minerals good for?What are minerals good for?
Where do we find mineral resources?Where do we find mineral resources?
Mineral resources from the earth’s crust
copper, lead, zinc, tin, platinum, copper, lead, zinc, tin, platinum, gold, silver, tungstengold, silver, tungsten
silicon, aluminum, iron, magnesiumsilicon, aluminum, iron, magnesiumtitanium, manganesetitanium, manganese
useful and useful and easily obtainableeasily obtainable
scarce and onlyscarce and onlyfound in concentratedfound in concentrated
localitieslocalities(ore deposits)(ore deposits)
Ore depositOre deposit – – localized concentration in the crust fromlocalized concentration in the crust fromwhich one or more minerals can be profitably extractedwhich one or more minerals can be profitably extracted
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Ore deposits are characterized by four (4) Ore deposits are characterized by four (4) distinctive aspects:distinctive aspects:1.1.Limited in supply – ore deposits must beLimited in supply – ore deposits must be sought after all over the earth. No countrysought after all over the earth. No country ever has all its own mineral resources.ever has all its own mineral resources.
United StatesArgonCoalCopperLeadLimestoneMolybdenumNitrogenSaltSilica (sand)tungsten
RussiaCoalCopperLeadManganeseNickelSaltTungstenZinc
AustraliaAluminumLeadNickelzinc
Brazilmanganese
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2. The quantity of a given mineral resource in anyThe quantity of a given mineral resource in any one country is rarely known with accuracy, and theone country is rarely known with accuracy, and the likelihood that new deposits will be found is hardlikelihood that new deposits will be found is hard to assess.to assess.
• Mineral deposits are easily exhausted Mineral deposits are easily exhausted over time. over time. • diatomaceous earth plant in Lompoc, CAdiatomaceous earth plant in Lompoc, CA
• D.E. deposit discovered in late 1800’sD.E. deposit discovered in late 1800’s• mine has been exhausted mine has been exhausted • currently producing poor quality currently producing poor quality diatomaceous earthdiatomaceous earth
Electron scanning microscope images
Hand specimen
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Aerial view of the Lompoc PlantAerial view of the Lompoc Plant
My processMy processengineer officeengineer office
GeologyGeologyofficeoffice
Crude ---- mined asCrude ---- mined asan open pitan open pit
4-systems producing4-systems producingdifferent grades of DEdifferent grades of DE
Use to eat lunch hereUse to eat lunch here
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3. Ore deposits are considered nonrenewableOre deposits are considered nonrenewable resources – take millions of years to formresources – take millions of years to form and just years to consume and just years to consume
Raises the Question:Raises the Question:
Is the earth’s supply of mineral resourcesIs the earth’s supply of mineral resourceslarge enough to meet the needs of thelarge enough to meet the needs of the
earth’s growing population?earth’s growing population?
Example:Example:Lompoc diatomaceous earth 6-10 million years ofLompoc diatomaceous earth 6-10 million years ofdeposition ---- only 100 years to exhaust the resourcedeposition ---- only 100 years to exhaust the resource
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4. Mining practices disturb the Earth’s surface.Mining practices disturb the Earth’s surface.• destruction of environmentally sensitive areasdestruction of environmentally sensitive areas
• Small-time miners mine the area and leave.Small-time miners mine the area and leave.
• United Nations estimates between 10-15 millionUnited Nations estimates between 10-15 million small-scale miners.small-scale miners.
• small-scale mining increases as population grows small-scale mining increases as population grows and the rate of mineral consumption increases.and the rate of mineral consumption increases.
4 km wide
1 km deep
Bingham Canyon Copper Mine
From SpaceFrom Space
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I I I I Earth Science better the thirdEarth Science better the third week. week.Earth Science better the thirdEarth Science better the third week. week.
I will get an A on my exams and quizzes.I will get an A on my exams and quizzes.
Discuss with a friend:Discuss with a friend:
1. Describe why there are a variety of 1. Describe why there are a variety of silicate tetrahedron configurations silicate tetrahedron configurations that form different silicate minerals.that form different silicate minerals.
2. Identify the 4 aspects relating to ore2. Identify the 4 aspects relating to ore deposits. deposits.
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