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Minerals Building Blocks of Rocks Minerals Building Blocks of Rocks.

Apr 01, 2015

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Page 1: Minerals Building Blocks of Rocks Minerals Building Blocks of Rocks.

MineralsBuilding Blocks of Rocks

MineralsBuilding Blocks of Rocks

Page 2: Minerals Building Blocks of Rocks Minerals Building Blocks of Rocks.

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

Page 3: Minerals Building Blocks of Rocks Minerals Building Blocks of Rocks.

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

Page 4: Minerals Building Blocks of Rocks Minerals Building Blocks of Rocks.

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)

Page 5: Minerals Building Blocks of Rocks Minerals Building Blocks of Rocks.

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

Page 6: Minerals Building Blocks of Rocks Minerals Building Blocks of Rocks.

increasing atomic increasing atomic numbersnumbers

Groups similarproperties

Periods

Non-m

etals

Non-m

etals

Metalloids

Metalloids

77

Page 7: Minerals Building Blocks of Rocks Minerals Building Blocks of Rocks.

Interpreting the PT-Interpreting the PT-

7979

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????

Page 8: Minerals Building Blocks of Rocks Minerals Building Blocks of Rocks.

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?

ICIC

Page 9: Minerals Building Blocks of Rocks Minerals Building Blocks of Rocks.

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

Page 10: Minerals Building Blocks of Rocks Minerals Building Blocks of Rocks.

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

Page 11: Minerals Building Blocks of Rocks Minerals Building Blocks of Rocks.

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

Page 12: Minerals Building Blocks of Rocks Minerals Building Blocks of Rocks.

The Ionic BondThe Ionic Bond – – electrically transferred electrically transferred electronselectrons

+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

Page 13: Minerals Building Blocks of Rocks Minerals Building Blocks of Rocks.

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

Page 14: Minerals Building Blocks of Rocks Minerals Building Blocks of Rocks.

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

Page 15: Minerals Building Blocks of Rocks Minerals Building Blocks of Rocks.

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)

Page 16: Minerals Building Blocks of Rocks Minerals Building Blocks of Rocks.

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

Page 17: Minerals Building Blocks of Rocks Minerals Building Blocks of Rocks.

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:

4. What part of the atom bonds together4. What part of the atom bonds together to form compounds?to form compounds?

5. Explain the differences between 5. Explain the differences between ionicionic, , covalentcovalent, , metallicmetallic, and Van der, and Van der Waals bondsWaals bonds. .

Page 18: Minerals Building Blocks of Rocks Minerals Building Blocks of Rocks.

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?

Page 19: Minerals Building Blocks of Rocks Minerals Building Blocks of Rocks.

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

Page 20: Minerals Building Blocks of Rocks Minerals Building Blocks of Rocks.

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:

6. What is the “5-part definition” of a6. What is the “5-part definition” of a mineral?mineral?

7. Name 3 substances that are NOT 7. Name 3 substances that are NOT minerals and 3 substances that areminerals and 3 substances that are minerals.minerals.8. Is ice a mineral? Is water a mineral?8. Is ice a mineral? Is water a mineral? why or why not?why or why not?

Page 21: Minerals Building Blocks of Rocks Minerals Building Blocks of Rocks.

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

Page 22: Minerals Building Blocks of Rocks Minerals Building Blocks of Rocks.

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

Page 23: Minerals Building Blocks of Rocks Minerals Building Blocks of Rocks.

Why do some minerals show their internal structure to the observer?Why do some minerals show their internal structure to the observer?

Page 24: Minerals Building Blocks of Rocks Minerals Building Blocks of Rocks.

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

Page 25: Minerals Building Blocks of Rocks Minerals Building Blocks of Rocks.

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.

Page 26: Minerals Building Blocks of Rocks Minerals Building Blocks of Rocks.

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

Page 27: Minerals Building Blocks of Rocks Minerals Building Blocks of Rocks.

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

Page 28: Minerals Building Blocks of Rocks Minerals Building Blocks of Rocks.

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:

9. What dictates a mineral’s crystalline9. What dictates a mineral’s crystalline structure?structure?

10. What conditions must be met to form10. What conditions must be met to form perfect crystal faces?perfect crystal faces?

11. Do all minerals show their crystalline11. Do all minerals show their crystalline structure to the observer (why/why not)?structure to the observer (why/why not)?

12. Describe the differences between 12. Describe the differences between amorphousamorphous and and crystallinecrystalline structures. structures.

ICIC

Page 29: Minerals Building Blocks of Rocks Minerals Building Blocks of Rocks.

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

Page 30: Minerals Building Blocks of Rocks Minerals Building Blocks of Rocks.

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

Page 31: Minerals Building Blocks of Rocks Minerals Building Blocks of Rocks.

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

Page 32: Minerals Building Blocks of Rocks Minerals Building Blocks of Rocks.

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: 13. How are minerals grouped? Name13. How are minerals grouped? Name at least four groups.at least four groups.

14. Name the two most common elements14. Name the two most common elements comprising the rock forming minerals.comprising the rock forming minerals.

15. Describe the characteristics of the silicate15. Describe the characteristics of the silicate tetrahedron.tetrahedron.

16. Why is the tetrahedron so strong?16. Why is the tetrahedron so strong?

Page 33: Minerals Building Blocks of Rocks Minerals Building Blocks of Rocks.

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