第1題TherearethreeprincipalrefractiveindicesoftheopticalaxesinBiaxialindicatrix.Itsmaximumvalueis____正確答案：:Ng第2題TherearethreeprincipalrefractiveindicesoftheopticalaxesinBiaxialindicatrix.Itsintermediatevalueis____正確答案：:Nm第3題Positivebiaxialcrystal,Np∥Bxa第4題TheplanewhichisperpendiculartoBxaofPositivebiaxialcrystalisNm-Np第5題Therelationshipbetweentheopticalaxisoftheindicatrixandthecrystallographicaxisisdefinedastheopticorientation.第6題OpticorientationoforthorhombicsystemisNg∥a,Nm∥b,Np∥c.第7題Themaximumbirefringencevalueofquartzis0.009,andthesectionofthemineralwiththemaximumbirefringencevalueis（）AThesectionofaparallelopticalaxisBThesectionofanobliqueopticalaxisCThesectionofaverticalopticalaxisDNotsure第8題BxamustbeperpendiculartoBxoinBiaxialindicatrix.第9題Positivebiaxialcrystal,Ng>Nm>Np第10題No=1.644andNe=1.624oftourmaline.Thebirefringenceoftheplanewhichisperpendiculartoopticalaxisoftourmalineis____正確答案：:0第11題TheopticalaxisOAofuniaxialcrystalisinthesamedirectionastheNeaxisandthec-axis第12題Thepositiveindicatrixofuniaxialcrystal，No＜Ne第13題Naturallightcanbepolarizedlightbythereflection,refractionandbirefringenceofcertainmaterials第14題Theamplitudeofnaturallightwavesisuniformlysymmetrical.第1題Whenbiotiteisdeepest,thedirectionofbiotitecleavageseamsrepresentsthevibrationdirectionofthelowerpolarizer.第2題Whenbiotiteisdeepest,thedirectionofbiotitecleavageseamsrepresentsthevibrationdirectionoftheupperpolarizer.Test3第1題Theisotropicmineralhasnopleochroism,andtherearenopositiveornegativerelief.第2題Inthesectionofparallelopticalaxisofuniaxialoropticalaxisplaneofbiaxial,thetwinklingismostobvious第3題Descendingtheobjectstage,thebeckelinemovesinthedirectionoflowerrefractiveindex第4題Liftingtheobjectstage,thebeckelinemovesinthedirectionofhigherrefractiveindex第5題Therefractiveindexofquartzis1.544-1.533.Theopticalpropertiesundertheplanepolarizerlensis:()ANegativehighreliefBPositivelowreliefCPositivemedianreliefDTwinkling第6題Thereliefgradeofapatite:()ANegativehighreliefBPositivelowreliefCPositivemedianreliefDTwinkling第7題Descendingmicroscopetube,thebeckelinemovesinthedirectionof____refractiveindex正確答案：:lower第8題Anysectionofanisotropicmineralhasfourtimesbrightanddarkextinctionphenomenaunderthecrossedpolarizer.第9題Thecleavageofplagioclaseishardtosee,becausetherefractiveindexvalueofplagioclaseisclosertothatofgum,andthecriticalangleissmallerincleavage第10題Thesectionwhichiscrosstoopticalaxisofanisotropicmineralhasnopleochroismandabsorption.第11題Thepleochroismformulaofhornblendeis:Ng=darkgreen,Nm=green,Np=lightyellowgreen,andtheabsorptionformulais____.正確答案：:Ng＞Nm＞NpTest4第1題IftheNpdirectionisparalleltothecaxisincolumnarminerals，theelongationdirectionofsectionsparalleltoz-axisarealllength-slow.第2題Thesignofelongateindifferentsectionsofthesamemineralmustbethesame.第3題Carlsbadtwininorthoclaseandplagioclase.第4題Thegypsumplate,alsoknownasλplate,canincreaseordecreasetheinterferencecolorofmineralsbyoneorder.第5題Whentheradiusofsamenamesoftwothinsectionsareparallel,theorderofinterferencecolorincreased第6題Whentheradiusofsamenamesoftwothinsectionsareparallel,theorderofinterferencecolor（）AmustbeincreasedBmustbedecreasedCnotnecessarilyincreasedDnotnecessarilydecreased第7題Theolivinehasgrainthreeorderblue-greeninterferencecolor,thephenomenonthattherotatingstagebecomesdarkiscalled____.正確答案：:extinction第8題Inthesamethinsection,pyroxeneandolivinehavedifferenthighestinterferencecolorsbecausetheyhavedifferentmaximumbirefringence.第9題Whenthecrystalgrowscrosstothec-axis,theelongationisconsistentwithopticalproperty.第10題ThehigherwhiteinterferencecoloriscausedbythehigherBirefringenceofthemineral.第11題Theinterferencecolordependsonlyonthemineralitself,andhasnothingtodowithotherfactors.第12題Whenthemineralisdecoloration,thetotalretardationbetweenthetwomineralsis0.Test5第1題Inthefollowinginterferograms,whichsectionisperpendiculartoopticalaxisofbiaxialcrystal?ABCD第2題Inthefollowinginterferograms,whichsectionisperpendiculartoBxaaxisof