Presentation is loading. Please wait.

Presentation is loading. Please wait.

Lecture 3 - Mineralogy

Similar presentations


Presentation on theme: "Lecture 3 - Mineralogy"— Presentation transcript:

1 Lecture 3 - Mineralogy

2 Atoms build Molecules build Minerals build Rocks build Earths Crust

3 Common minerals that we mine and use. Mineral NameWhat It IsUses ChallcopyriteCopper-iron-sulfur mineral; CuFeS 2 Mined for copper FeldsparLarge mineral family; aluminum-silicon-oxygen composition; decomposes to form clays; x(Al,Si) 3 O 8, where x = various elements like sodium, iron Ceramics and porcelain FluoriteCalcium-fluorine mineral; CaF 2 Mined for fluorine (its most important ore); steel manufacturing GalenaLead and sulfur mineral; PbS, the leading ore for lead Mined for lead GraphitePure carbon; C,Pencil lead (replacing the actual lead metal once used in pencils); dry lubricant GypsumHydrous-calcium-sulfur mineral; CaSO 4 – 2H 2 O Drywall, plaster of Paris HaliteSodium-Chloride; NaClTable salt, road salt, sodium, chlorine HematiteIron-oxygen mineral; Fe 2 O 3 Mined for iron MagnetiteIron-magnesium-oxygen mineral; (Fe,Mg)Fe 2 O 4 Mined for iron PyriteIron-sulfur mineral; FeS 2 Mined for sulfur and iron QuartzSilicon-oxygen mineral; SiO 2 In pure form, for making glass SphaleriteZinc-iron-sulfur mineral; (Zn,Fe)SMined for zinc TalcMagnesium-silicon-oxygen-hydrogen mineral; Mg 3 Si 4 O 10 (OH) 2 Used in ceramics, paint, talcum powder, plastics and lubricants CalciteCalcium carbonate CaCo 3 Toothpaste, cement, drywall

4 Bingham Copper Mine – copper, silver, gold, molybdenum

5 Page: 28 [FCS1] Source?[FCS1] Page: 28 [FCS2] According to Gloss of Geol, used in mfr of glass, enamel, HF acid; steel not mentioned. ???[FCS2] What is a Mineral? A mineral is a naturally occurring, inorganic solid with an orderly internal arrangement of atoms (called crystalline structure) and a definite, but sometimes variable, chemical composition

6 Hawaiis most common mineral – volcanic Olivine Hawaiis second most common mineral – marine Calcite

7 Eight Abundant Elements in Crust oxygen46%(O 2- ) silicon28%(Si 4+ ) aluminum8%(Al 3+ ) iron6%(Fe 2+ or Fe 3+ ) magnesium4%(Mg 2+ ) calcium2.4%(Ca 2+ ) potassium2.3%(K 1+ ) sodium2.1%(Na 1+ ) How are minerals built?

8 Review the structure of an atom

9 Structure of the Atom - 8 If we drew a hydrogen atom to scale, making the nucleus the diameter of a pencil, the electron would orbit about 0.5 km from the nucleus. The whole atom would be the size of a baseball stadium…with so much empty space, how can our world feel so solid? Octet Rule…filled outer orbital Atomic Number…number of protons Mass Number…number of protons and neutrons

10 Isotopes of an atom have variable number of neutrons (mass number) Most atoms exist in a charged state due to the need to have a filled outer shell - Ions

11 Eight Abundant Elements in Crust oxygen46%(O 2- ) silicon28%(Si 4+ ) aluminum8%(Al 3+ ) iron6%(Fe 2+ or Fe 3+ ) magnesium4%(Mg 2+ ) calcium2.4%(Ca 2+ ) potassium2.3%(K 1+ ) sodium2.1%(Na 1+ ) How are minerals built?

12 Octet Rule

13 Chlorine = 7 electrons in outer shell Sodium = 1 electron in outer shell NaCl Ionic Bonding 7 e- in outer shell 1 e- in outer shell

14 Covalent Bonding Oxygen = 6 electrons in outer shell Hydrogen = 1 electron in outer shell H 2 0 Polar molecule

15 46% oxygen (O 2- ) 28% silicon (Si 4+ ) 8% aluminum (Al 3+ ) 6% iron (Fe 2+ or Fe 3+ ) 4% magnesium (Mg 2+ ) 2.4% calcium (Ca 2+ ) 2.3% potassium (K 1+ ) 2.1% sodium (Na 1+ ) These elements in a magma chamber bond and form minerals as the magma loses heat

16 Slow cooling allows fewer (larger) crystals = coarse texture to rock Rapid cooling leads to many small crystals = smooth texture to rock Crystallization

17 Most abundant elements? – silicon and oxygen Silicon has 4 electrons in outer shell = needs 4 more. Oxygen has 6 electrons in outer shell = needs 2 more. Oxygen still needs 1 more electron each (SiO 4 ) 4-

18 Silica tetrahedrons will form minerals with crystalline structure consisting of unlinked tetrahedra, chains, double chains, and sheets.

19 Chains of silicates form because Oxygen bonds with Silicon a second time Single tetrahedron Single chain Double chain Silicate sheet (SiO 4 ) 4- (SiO 3 ) 2- (Si 4 O 11 ) 6- (Si 2 O 5 ) 2- Three-dimensional framework (Si 3 O 8 ) 4-

20 Silicon tetrahedrons form chains Metallic cations fit inside the chains (SiO 3 ) 2- aluminum (Al3+) iron (Fe2+ or Fe3+) magnesium (Mg2+) calcium (Ca2+) potassium (K1+) sodium (Na1+)

21 Pairs of cations that substitute for each other Cations move into spaces in silicate structures, but they will only form compounds that have no charge – neutral (positive charges must equal negative charges)

22 Silicon tetrahedrons form chains Metallic cations fit inside the chains (SiO 3 ) 2- aluminum (Al3+) iron (Fe2+ or Fe3+) magnesium (Mg2+) calcium (Ca2+) potassium (K1+) sodium (Na1+) One cation may push another out of the latticework Substitution Mg Fe Ca Na Single substitution Double substitution Si Al Must result in a neutral compound

23 Charge Size (nm) 46% oxygen (O 2- ) % potassium (K 1+ ) % iron (Fe 2+ or Fe 3+ ) % magnesium (Mg 2+ ) % silicon (Si 4+ ) % aluminum (Al 3+ ) % calcium (Ca 2+ ) % sodium (Na 1+ ) Cation Substitution: Mineral must be neutral Na/Ca, Al/Si and Fe/Mg Olivine: single tetrahedron (SiO 4 ) 4- [Fe 2 2+ (SiO 4 ) 4- ] or [Mg 2 2+ (SiO 4 ) 4- ] –8=0 or –8=0 Atoms in a pair push each other out of position Feldspar: 3-D framework (Si 3 O 8 ) 4- [Na 1+ Al 3+ Si 3 4+ O 8 2- ]or [Ca 2+ Al 2 3+ Si 2 4+ O 8 2- ] –16=0 or –16=0 Single Substitution Fe Mg Double Na Ca Substitution Al Si

24 As the Si and O build crystalline structures and the metallic cations play single and double substitution, the entire magma chamber grows into a solid mass of minerals….


Download ppt "Lecture 3 - Mineralogy"

Similar presentations


Ads by Google