module 5b - minerals, identification

8/18/2019 Module 5B - Minerals, Identification

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Module 5BModule 5BMinerals: identificationMinerals: identification


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QuestionsQuestions

How can you identify minerals?How can you identify minerals?

How do geologists identifyHow do geologists identify

minerals?minerals?

Identification of Minerals


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Identifying Physical Properties of MineralsIdentifying Physical Properties of Minerals

1.1. Crystal formCrystal form

2.2. Color Color 3.3. StreakStreak

4.4. Luster Luster

5.5. CleavaeCleavae

!.!. "racture"racture#.#. $ardness$ardness

%.%. &enacity&enacity

'.'. S(ecific ravityS(ecific ravity

1).1). &aste&aste

11.11. ManetismManetism

12.12. *eaction +it, acid*eaction +it, acid

13.13. StriationsStriations


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1. Crystal form1. Crystal form

Is a set of crystalline faces ,avin a definiteIs a set of crystalline faces ,avin a definiteeometric relations,i( to one anot,er eometric relations,i( to one anot,er

-arnet-arnet

uart/uart/



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Colors of ru0y and sa((,ireColors of ru0y and sa((,ire

varieties of corundum lvarieties of corundum l2233

2. Color 2. Color

Is due to visi0le +avelent,s of li,t not a0sor0edIs due to visi0le +avelent,s of li,t not a0sor0ed

Is t,e most o0vious 0ut least relia0le (ro(erty to useIs t,e most o0vious 0ut least relia0le (ro(erty to usefor identificationfor identification

Smoky 6uart/

Colors of 7arieties of uart/Colors of 7arieties of uart/

Milky 6uart/

met,yst

Citrine



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"iure 1.%"iure 1.%

3. Streak3. Streak

&,e color of a mineral in (o+der form&,e color of a mineral in (o+der form



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4.4. LusterLuster

Is t,e intensity of li,t reflected from a surfaceIs t,e intensity of li,t reflected from a surface

Have a metallic luster Have a metallic luster

Has a nonmetallic luster Has a nonmetallic luster

8yrite

-alena

8otassium felds(ar



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5. Cleavae5. Cleavae

Is 0reakae alon (lanes of +eaknessIs 0reakae alon (lanes of +eakness

Is due to +eak 0ondin 0et+een t,ose (lanesIs due to +eak 0ondin 0et+een t,ose (lanes



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Various Types of CleavageVarious Types of Cleavage


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Pyramidal Cleavage Cubic Cleavage, and Rhombohedral CleavagePyramidal Cleavage Cubic Cleavage, and Rhombohedral CleavageDisplayed by Fluorite, Halite, and CalciteDisplayed by Fluorite, Halite, and Calcite

"luorite"luorite$alite$alite

CalciteCalcite



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Identifying Physical Properties of MineralsIdentifying Physical Properties of MineralsDistinguishing between Cleavage Planes and Crystal FacesDistinguishing between Cleavage Planes and Crystal Faces

•Cleavage PlanesCleavage Planes Repeated li!e a seriesRepeated li!e a series

of step or terraces of step or terraces

• " crytal face " crytal face

" single surface " single surface #o repetitions of the#o repetitions of the

crystal face within crystal face within

a crystal a crystal


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!. "racture!. "racture Is 0reakae in random directionsIs 0reakae in random directions

Is due to t,e a0sence of +eak 0ondin 0et+een (lanesIs due to t,e a0sence of +eak 0ondin 0et+een (lanes Conc,oidal fracture yields scallo(ed edes like in 0roken lassConc,oidal fracture yields scallo(ed edes like in 0roken lass



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#. $ardness#. $ardness Is t,e resistance to scratc,inIs t,e resistance to scratc,in

Is 0ased on t,e Mo,9s ScaleIs 0ased on t,e Mo,9s Scale 1 talc1 talc 2 y(sum2 y(sum 3 calcite3 calcite

4 fluorite4 fluorite 5 a(atite5 a(atite ! (otassium felds(ar ort,oclase! (otassium felds(ar ort,oclase # 6uart/# 6uart/

% to(a/% to(a/ ' corundum' corundum 1) diamond1) diamond



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%. &enacity%. &enacity

resistance to 0reakin or 0endinresistance to 0reakin or 0endin

'. S(ecific ravity: an e(ression of ,eaviness'. S(ecific ravity: an e(ression of ,eaviness

density of a su0stancedensity of a su0stance ;;


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12. *eaction +it, acid12. *eaction +it, acid

minerals containin a Cminerals containin a C33

ion fi// release Cion fi// release C22

+,en +,en

in contact +it, ,ydroc,loric acidin contact +it, ,ydroc,loric acid

2$Cl > CaC2$Cl > CaC33 ?? Ca Ca2>2> > 2Cl > 2Cl@@ > $ > $22 > C > C22

13. *eaction +it, acid Striations13. *eaction +it, acid Striations re sa+@toot, lines (resent on crystal (lanes due tore sa+@toot, lines (resent on crystal (lanes due to

lamellar t+innin re(etition of crystals on t,at (lanelamellar t+innin re(etition of crystals on t,at (lane

Striations are c,aracteristic of (laioclase felds(arStriations are c,aracteristic of (laioclase felds(ar

calcite dolomite alena and s(,aleritecalcite dolomite alena and s(,alerite


module 5b - minerals, identification

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