Mineralogy 2 Flashcards
symmetry elements of a point group are: 3 crystallogrpahic axes of 2-fold symmetry and 3 mirror planes perpendicular to the crystallographic axes. The Hermann-Maugin notation of the point group is:
2/m2/m2/m
Sphalerite, willemite, and smithsonite are all
zinc ores
Talc-kyanite assemblage can stabilize in
eclogite facies pelitic rocks
members of the phyllosilicate group are
chlorite, talc, wavellite
In granitic rocks composed of the ff collection of minerals: amphibolite, biotite, albite, andesine, quartz
which weather first?
Andesine
Which of the ff statements about igneous rocks is correct?
a. tholeiitic rocks are alkaline, but calc-alkaline rocks are subalkaline in nature
b. tholeiitic and calc-alkaline rocks are both subalkaline in nature
c. tholeiitic rocks are subalkaline, but calc-alkaline rocks are alkaline in nature
d. tholeiitic and calc-alkaline rocks are both alkaline in naure
b. tholeiitic and calc-alkaline rocks are both subalkaline in nature
The ratio of bridging to non-bridging oxygen atoms is zero in case of
nesosilicates
siliciclastic sedimentary rock with <5% matrix and QFL composition of 60% quartz, 30% rock fragments and 10% feldspar is called:
lithic arenite
which mineral family produces the most clay minerals during weathering processes?
feldspar
given the ff minerals: bastnaesite, didymium, loparite, and monazite
what elements are you looking for?
U
it is the mangnesium end -member of olivine series
forsterite
in the metamorphic reaction Quartz + Muscovite = X + Sillimanite + Water, ‘X’ represents
Orthoclase
W/c one of the ff rocks is associated with metamorphic thermal aureoles?
a. chlorite schist
b. glaucophane schist
c. amphibolite
d. hornfels
d. hornfels
W/c of the ff clay minerals contain potassium (K)?
a. kaolinite
b. illite
c. vermiculite
d. montormorillonite
b. illite
copper ores would be found in which of the following groups of minerals?
a. stannite, enargite, bornite
b. bornite, chalcocite, enargite
c. stannite, chalcocite, bastnaesite
d. cuprite, bastnaesite, bornite
b. bornite, chalcocite, enargite
Which of the following clay sequences of minerals CORRECTLY list an increasing rate of dissolution during chemical weathering?
a. olivine-quartz-pyroxene-orthoclase
b. olivine-pyroxene-orthoclase-quartz
c. quartz-olivine-orthoclase-pyroxene
d. quartz-orthoclase-pyroxene-olivine
d. quartz-orthoclase-pyroxene-olivine
Which one of the ff combination of reservoir and cap rock respectively, is suitable for oil accumulation?
a. sandstone-conglomerate
b. limestone-sandstone
c. shale-limestone
d. dolomite-evaporite
d. dolomite-evaporite
Which of the ff minerals is a member of the pyralpsite group of garnet minerals?
a. andradite
b. grossular
c. uvarovite
d. sepssartine
d. sepssartine
on inserting a first order interference filter in SE-NW direction, the interface figure of quartz shows
a. yellow in NE, SW quadrants and blue in NW, SE quadrants
b. yellow in NE, NW and blue in SW, SE
c. blue in NE, SW and yellow in NW, SE
d. blue in NE, NW and yellow in SW, SE
c. blue in NE, SW and yellow in NW, SE
in metafites, w/c one of teh ff mineral assemblages is stable under greenschist facies conditions?
a. andesine + biotite + hornblende
b. oligoclase + epidote + biotite + hornblende
c. albite + chlorite + actinolite + epidote
d. oligoclase + biotite + hornblende
c. albite + chlorite + actinolite + epidote
epidote, piemontite, and allanite belong to what silicate group?
sorosilicates
glaucophane schist forms in
a. subduction zones
b. pull-apart basins
c. mid-oceanic ridges
d. continental rifts
a. subduction zones
the ff mienrals are polymormph of Al2SiO5, EXEPT:
a. sillimanite
b. andalusite
c. kyanite
d. fuschsite
d. fuschsite
in what type of environment would you expect to find deposits of gold, platinum, and titanium?
placer deposits
a siliciclastic sedimentary rock consisting predominantly of the same type of gravel-size clasts is called
oligomict conglomerate
melanocratic porphyritic rock containing phenocrysts of biotite, with feldspar restricted to the groundmass, is called
lamprophyre
surface exposure, in a temperature climate of aluminum silicate minerals such as feldspar would result in the development of
biotite
with increasing activity of silica, the correct ORDER of appearance of minerals in a weathering environment with constant ratio of activities of K+ and H+ is
a. gibbsite-pyrorphyllite-kaolinite
b. pyrophyllite-gibbsite-kaolinite
c. gibbsite-kaolinite-pyrophyllite
d. kaolinite-gibbsite-pyrophyllite
c. gibbsite-kaolinite-pyrophyllite
which one of the ff mineral shows internal reflection
a. molybdenite
b. pyrite
c. orpiment
d. magnetite
c. orpiment
the reaction muscovite + quartz = k-feld + sillimanite + water takes within what facies?
amphibolite facies
describes a crystal with fully-developed faces
euhedral
in some volcanic rocks, large phenocrysts are usually surrounded by small crystals. this is due to
ostwald ripening
a common type of twinning in plagioclase composed of alternating lamellae
polysynthetic twinning
which is not a pyroxene
a. diopside
b. augite
c. orthpyroxene
d. sanidine
d. sanidine
bentonite, a deposit w/c can cause problems associated with swelling in the presence of water is formed
a. by evaporation of ancient lake beds
b. from the alteration of volcanic ash
c. during a time of geologic quiescence
d. by deposition in a lagoonal environment
b. from the alteration of volcanic ash
the ff minerals are cyclosilicates, except:
a. pyroxene
b. cordierite
c. axinite
d. tourmaline
a. pyroxene
of the ff iron minerals, w/c is the least stable in a humid, temperature climate
a. pyrite
b. ilmenite
c. geothite
d. hematite
a. pyrite
the most abundant mineral in the earth’s crust
plagioclase feldspar
subclass of silicate group characterized by Si:O ratio of 1:2
a. tectosilicates
the following minerals are polymorphs of quartz, except:
a. coesite
b. cristobalite
c. stishovite
d. leucite
d. leucite
used to describe a mineral having some optical properties in all dimensions
isotropic
w/c of the ff is uniaxial positive
a. garnet
b. calcite
c. gold
d. quartz
quartz
blueschist facies rocks are found in a metamorphic belt resulting from
low temp, high pressure
type of optical path where light travels straight from the source to the ocular
orthoscopic illumination
to observe a mineral in a thin section under XPL, what part of the microscope should you insert? assume that the lower polarizer is already inserted
analyzer
standard thickness of thin section
30 microns
the bright, narrow band of light that appears at the interface between the mineral an the mounting medium
Becke line
silicate group that has a Si:O ratio of 4:11
double chain inosilicates
w/c of the ff minerals is the least stable during the chemical weathering process in temperate climate
a. olivine
b. clay minerals
c. fe-oxides
d. quartz
olivine
the chart that is used to determine orders of interference figure is called
Michel-Levy Chart
the center of the cross of an interference figure is called
melatope
w/c of the ff is a gem of corundum
a. sapphire
b. alexandrite
c. emerald
d. amethyst
sapphire
assemblage of albite, chlorite, actinolite, and calicte would be most characteristic of what facies
greenschist facies
w/c mineral is used as a n industrial substitute for asbestos?
wollastonite
