Mineralogy and Petrology Flashcards
Crystal habit characterized by branching, tree-like clusters similar to dendritic.
Arborescent
Which of the following minerals exhibits a splendent luster?
a. Quartz
b. Galena
c. Mica
d. Feldspar
Galena
What is the index of refraction for Canada Balsam?
1.54
Which of the following is NOT part of the calcite group?
a. Magnesite
b. Siderite
c. Rhodochrosite
d. Dolomite
Dolomite
What is the most common method for dissolving silver?
A) Hydrochloric acid
B) Sulfuric acid
C) Nitric acid
D) Phosphoric acid
Nitric Acid
What is the color of K-felds during staining?
A) Red
B) Blue
C) Green
D) Yellow
Yellow
What is the typical magnification used for observing interference figures in thin sections?
A) 5x
B) 10x
C) 25x
D) 45x
25x
Cerargyrite is a mineral of:
A) Silver
B) Copper
C) Gold
D) Lead
Silver (-arg = Argentum)
What is the typical operating cut-off grade for a porphyry copper deposit?
A) 0.1-0.3% Cu
B) 0.3-0.5% Cu
C) 0.5-0.7% Cu
D) 0.7-1.0% Cu
0.3-0.5% Cu
What type of deposit is found in Almaden, Spain?
A) Gold
B) Silver
C) Mercury
D) Copper
Mercury
What is the primary use of agalmatolite/pagodite?
A) Gemstone
B) Carving stone
C) Building material
D) Ore of aluminum
Carving Stone
Where is the Argyle Diamond Pipe located?
A) South Africa
B) Russia
C) Canada
D) Australia
Australia
Which of the following minerals contains the gem variety alexandrite?
A) Corundum
B) Beryl
C) Chrysoberyl
D) Topaz
Chrysoberyl
Theory that proposes that beams of light consist of material particles that spread in all directions from luminous bodies.
Corpuscular Theory
If bright fringes form on the edges of the mineral fragments facing toward the darkened side of the visible field and dark fringes facing the bright side of the field, the refractive index of the mineral fragments is _________ than that of the immersion oil
Answer: Greater
Dark side vs Light side (Greater)
Dark side and Dark side (Lesser)
The direction of movement of the Becke Line is determined by lowering the stage (or raising the objectives) with the Becke Line always moving into the material with the ________ refractive index
Higher
The angle of incidence will bend towards the normal when…
When the light is passing from a medium in which it travels fast into one in which it travels slow.
RI of Water
1.33
The indicatrix of isotropic minerals which is geometrically a sphere, an indicatrix of constant radius, due to light travelling in all directions with the same velocity.
Isotropic Indicatrix
Describe the retardation if the slow direction of the accessory plate corresponds to the slow direction of the mineral and vice versa. What are the colors associated with these retardations?
If the slow direction of the accessory plate corresponds to the slow direction of the mineral, retardation will add and we will see higher order interference colors (produces light blue). If they do not correspond, retardation will, in part, cancel and we will see lower order colors (light yellow).
What color is displayed in a negative optic axis of the uniaxial mineral in a NE-SW direction?
Yellow
An accessory plate used for minerals with low birefringence in order to determine their optic sign by retarding the mineral by 550 um or specifically, one order.
Gypsum plate
A Biaxial interference figure characterized by:
- Thick NS isogyre
- Thin EW isogyre
- Two melatopes on each side of the EW isogyre and are the two optic axes themselves.
Centered Acute Bisectrix (Bxa) figure
A biaxial interference figure characterized by:
- Two melatopes are visible if 2V is less than 30, only one is seen if not
- isogyre straighten once parallel to the cross hair but curves when rotated
Centered biaxial optic axis
What color is displayed in a negative optic axis of the biaxial mineral in the center of Bxa or on the convex part of the isogyres?
Blue
Observed when the Bxo (X- or Z-normal stage) is perpendicular to the stage, with the Bxa and optic normal lying in the plane of the stage. Usually have thick isogyres.
Centered Obtuse Bisectrix
Biaxial interference figure observed when the optic normal is perpendicular to the stage.
Biaxial flash figure
What solution does Aragonite stain black?
Feigl Solution
Which solution stains Calcite Lilac?
a. Meigen
b. Harris Hematoxilin Solution
c. Cobalt Nitrate
d. Organic Dye Alizarin Red
Answer: Harris Hematoxilin Solution
a. Meigen (Aragonite - Purple)
c. Cobalt Nitrate (Aragonite - Lilac)
d. Organic Dye Alizarin Red (Dolomite - Lilac)
Which solution stains Calcite green?
a. Lemberg Hydroxide
b. Silver Chromate
c. Trypan
d. Copper Nitrate
Answer: Copper Nitrate
a. Lemberg Hydroxide (Brown)
b. Silver Chromate (Red Brown)
c. Trypan (Blue)
The following blue-staining solutions stain dolomite blue except the two:
a. Benzidene
b. Trypan Blue
c. Magneson
d. Potassium Ferricyanide
Benzidene (Rhodochrosite - Blue) and Magneson (Smithsonite - Light Blue, Magnesite - Deep Blue)
is a symmetry operation that combines translation (t) or (c) parallel to a mirror plane (m) with reflection across the mirror
Glide Reflection
It is the reciprocal of Miller indices
Weiss Parameters
This crystal form cannot exist alone in perfectly formed (euhedral) crystals and must occur in combination with other crystal forms.
Open crystal forms
Defect are formed when the ions in question move to an interstitial site, leaving unoccupied structural sites or holes behind. These defects combine omission and interstitial defects. Because the ion has simply moved to another location, the overall charge balance of the crystal is maintained, but local lattice distortions occur in the vicinities of both the holes and the extra ions
Answer: Frenkel Defects
Schottky defect - An equal number of cations and anions are missing from their lattice sites, creating vacancies. This defect is common in compounds with similar-sized ions, such as NaCl and CsCl. It decreases the density of the substance and overall charge balance is not maintained.
Defects either are formed when the ions migrate out of the crystal structure or were never there. These defects create a charge imbalance in the crystal lattice. Such charge imbalances may be balanced by the creation of a second hole in the crystal structure; for example, an anion omission may be created to balance a cation omission
Schottky defects
transformations that involve the conversion of one polymorph into another through bond breakage so that a significant change in structure occurs. Such transformations require large amounts of energy, and this requirement tends to slow or inhibit their occurrence.
Reconstructive transformations
Transformations between polymorphs that do not require bonds to be broken and involve only small rotations of atoms into the new structural arrangement are called __________ and tend to occur very rapidly under the conditions predicted by laboratory experiments and theory.
displacive transformations
Minerals that are macroscopically transparent often possess a (what color) streak?
White
What is the length of one birefringence order?
550um
What are the magnification of low, medium, and high power objectives?
2.5-4x, 8-10x, and 40-60x respectively
Microcline can generally be distinguished from other potassium feldspars such as sanidine and orthoclase by its complex twinning. The twins appear as spindle - shaped crystals that are intergrown at a high angle, giving rise to what is variously called _________.
gridiron or scotchplaid twinning
Non - uniform extinction can result from the _________________. This distorts the crystal structure in a manner that causes different parts of the crystal to go to extinction at different times as the stage is rotated.
deformation of crystals associated with strain
What is a solid solution?
a. Mixture of certain specific compounds
b. Frozen liquid solution
c. Mixed crystalline form
d. Crystals formed by solidification of lava
Mixed crystalline form
Which of the crystal system has two divisions?
a. Isometric
b. Tetragonal
c. Hexagonal
d. Orthorhombic
Hexagonal system is often divided into two subcategories: the hexagonal and trigonal systems
Which of the following minerals crystallizes in the isometric system?
a. Axinite
b. Pyrite
c. Cassiterite
d. Anatase
Pyrite
a. Axinite (Triclinic)
c. Cassiterite (Tetragonal)
d. Anatase (Tetragonal)
Which one of the following minerals belongs to the tetragonal
system?
a. Cassiterite
b. Fluorite
c. Quartz
d. Hematite
Cassiterite
b. Fluorite (Cubic)
c. Quartz (Trigonal)
d. Hematite (Hexagonal)
One of the following minerals belongs to the hexagonal system.
Which one?
a. Celestite
b. Halite
c. Zircon
d. Calcite
Celestite
b. Halite (cubic)
c. Zircon (tetragonal)
d. Calcite (trigonal/rhombohedral)
To the orthorhombic system belongs one of the following minerals.
Name it.
a. Orthoclase
b. Axinite
c. Topaz
d. Chalcopyrite
Topaz
a. Orthoclase (Monoclinic)
b. Axinite (Triclinic)
d. Chalcopyrite (tetragonal)
Can you tell which one of the following mineral crystals belongs to
the monoclinic system?
a. Albite
b. Gypsum
c. Cinnabar
d. Corundum
Gypsum
a. Albite (Triclinic)
c. Cinnabar (Trigonal)
d. Corundum (Trigonal)
The crystal form of one of the following minerals falls in the triclinic
system. Which one?
a. Staurolite
b. Augite
c. Aragonite
d. Rhodonite
Rhodonite
a. Staurolite (Monoclinic)
b. Augite (Monoclinic)
c. Aragonite (Orthorhombic)
What is the face parallel to the vertical axis in a crystal called?
a. Prism
b. Pinacoid
c. Dome
d. Pyramid
Pyramid
The father and son duo W. H. and W. L. Bragg won the Nobel Prize
for Physics in 1915 for which development connected with
crystallography?
a. Crystal classes
b. Refractometry
c. X-ray diffraction
d. Goniometry
X-ray diffraction
What is the function of Nicol prisms in a petrological microscope?
a. To break light into primary colors
b. To produce polarized light
c. To identify inclusions in minerals
d. To determine order of colors
To produce polarized light
What is measured by a goniometer?
a. Scattering of light in a crystal
b. Interfacial angles of crystals
c. Optic axes of crystals
d. Area of a crystal face
Interfacial angles of crystals
A particular device is used in a polarizing microscope to measure
orientation of minerals.
Fedorov stage
Sir C. V. Raman got the Nobel Prize for Physics in 1930 for
discovering the light effect named after him. Which mineral was used by
him for his experiments?
a. Zircon
b. Calcite
c. Diamond
d. Quartz
Diamond
Where can a kelyphitic rim be found?
a. Around a volcano
b. Pyroxene or amphibole around olivine
c. Rutile growing on hematite
d. Brilliant cornea around a diamond
Pyroxene or amphibole around olivine
If you found splendent luster in a mineral, what would you see?
a. Brilliant glass-like
b. Shining silk-like
c. Reflecting mirror-like
d. Brilliant diamond-like
Reflecting mirror-like
Which of the following minerals is not formed by evaporation?
a. Carnallite
b. Halite
c. Montmorillonite
d. Sylvite
Montmorillonite
a. Carnallite KMgCl3·6(H2O)
b. Halite
d. Sylvite
Which of the following is a monoclinic feldspar?
a. Anorthoclase
b. Celsian
c. Andesine
d. Bytonite
Celsian, all else Triclinic
Nacre is the layers of which a pearl is made of. What mineral is it?
a. Gypsum
b. Aragonite
c. Bornite
d. Anhydrite
Aragonite
Which mineral has hardness that varies enormously from its face to face?
a. Garnet
b. Corundum
c. Zircon
d. Diamond
Garnet
Which is the element whose polymorphs range from the softest to hardest?
a. Sulphur
b. Carbon
c. Silicon
d. Calcium
Carbon
Which of the following variety of diamond is the toughest?
a. ballas
b. bort
c. carbonado
d. carborundum
carbonado
textures characteristic of a post- metamorphic event, e.g. alteration, weathering, … etc.
Superimposed textures
suffix-blast or -blastic indicates that a feature is of ____________ origin
metamorphic
prefix blasto- (meaning that a feature is ___________________________)
not of metamorphic origin but is inherited from the parent rock
where the interlocking randomly oriented crystals are somewhat elongate, prismatic or subidioblastic. Usually applied to rocks with one or two mineral species only.
a. Granoblastic polygonal
b. Granoblastic interlobate
c. Granoblastic amoeboid
d. Granoblastic decussate
Granoblastic decussate
where the interlocking randomly oriented crystals are somewhat elongate, prismatic or subidioblastic. Usually applied to rocks with one or two mineral species only.
a. Granoblastic polygonal
b. Granoblastic interlobate
c. Granoblastic amoeboid
d. Granoblastic decussate
Granoblastic decussate
where all the grains have irregular outlines, and all the minerals are anhedral
a. Granoblastic polygonal
b. Granoblastic interlobate
c. Granoblastic amoeboid
d. Granoblastic decussate
Granoblastic amoeboid
a deformed rock with a texture that records the deformation
Tectonite
It involves heating a material above its recrystallization temperature, maintaining a suitable temperature for an appropriate amount of time and then cooling. In this process, atoms migrate in the crystal lattice and the number of dislocations decreases, leading to a change in ductility and hardness.
Annealing
where the inclusions define a spiral shaped trail, which may have developed from the “rolling over” of the poikiloblasts. Garnet is famous for this
Snowball
a metamorphosed fine-grained sedimentary rock
Pelite
Where the poikiloblasts overgrow the pre-existing foliation. This texture therefore indicates post-tectonic crystallization of the poikiloblasts
Helicitic
develops in serpentinites, where the serpentine minerals replace the granular olivine crystals giving rise to hour-glass like appearances
Hour-glass texture
is characterized by optical continuity between the mineral and its overgrowth. Both the mineral and the overgrowth must belong to the same structural group, and may possibly be the same mineral. This type of overgrowth is controlled fully by the the matrix mineral.
Epitaxial overgrowth (Reaction Texture)
One mineral overgrows another of a similar structure (e.g. Actinolite rims on glaucophane, both monoclinic). Orientation of overgrowing mineral is controlled by that of the overgrown one
Topatactic Replacement (Reaction Texture)
a replacement of one mineral along its rim by an intergrowth of two or more minerals, in a way that the new minerals almost completely surround the mineral being replaced
Kelyphitic texture (Reaction Texture)
Monomineralic coronas are also known as
Moats
several concentric layers of one or more minerals completely encircling an older phase. The layers (which range from one to five in number) represent asequence of reactions that have taken place (none to completion) to replace the mineral in the core
Corona Texture (a reaction texture)
where the core of a mineral is dissolved or replaced leaving behind a surviving rim. Such textures usually form due to an original compositional zoning within the mineral with the replaced core
Atoll texture (A reaction texture)
Are irregular fine-grained mineral intergrowths that form as a result of a certain reaction that did not go to completion. These intergrowths are often recognized by their wormy appearance and often occur along the boundaries of reacting minerals
Symplectites (also a reaction texture)
Hornfelsic texture is a non-foliated metamorphic texture that is characterized by a very fine-grained (<1mm), dense texture. This texture is common in metamorphic rocks that have been formed by contact metamorphism, where rocks have been heated by hot magma or lava
Hornfelsic Texture
are granoblastic calc - silicate rocks formed by contact metamorphism of carbonate country rocks such as limestone or dolostone
Skarns , also known as tactites
Sodium-rich basalts and andesites
Spilites and keratophyres respectively
This rock may be one of the driving forces for plate motion. The slab - pull effect generated by such rock in subducted slabs is thought to drive mantle convection and plate motion.
Eclogite (3.5-4 g/cc)
What is a diatreme?
a. Intrusive igneous body
b. vulcanic plug
c. vertical vent containing breccia and older rocks
d. volcanic vent piercing sedimentary strata
vertical vent containing breccia and older rocks
What is an intrusion which domes the overlying rocks after piercing
lower layers called?
a. Batholith
b. laccolith
c. phacolith
d. diapir
laccolith
Hydrous minerals are stable in _______, which begin to form at temperatures of ∼ 300 ° C
Schists
which refers to the thin, sill - like intrusion of magma into parallel country rock layers.
Lit par lit intrusion
Percent Matrix of Protomylonite
10-50%
are metaquartzites that contain 20 – 30% iron and are also commonly banded.
Taconites
In asymmetrical porphyroclasts or porphyroblasts, what is the indicator of shear direction?
Mineral tails that points in the direction of shear
_______ grain tail complexes consist of wedge-shaped tails that do not cross the reference plane of shear.
Sigma (σ) grain tail complex
_______ grain tail complexes are produced by relatively rapid grain rotation relative to tail growth rate so that parts of the tail crosses the reference plane.
Delta (δ) grain tail complexes
_______ grain tail complexes that have no discernible indication for shear directions because the images of the tails are symmetrical/mirrored.
Theta (θ) grain tail complexes
are lines drawn on geological maps that mark the fi rst appearance of a particular index mineral.
isograds
rocks that compose the bulk of many metamorphic aureoles, forming at temperatures and pressures generally at 450-600C and <2.5kbar
Hornblende hornfels facies
The facies, with temperatures generally < 450 ° C and pressures < 2 kbar (depth < 6 km). It develops in the outer fringes of many metamorphic aureoles.
Albite-Epidote Facies
Which among the following is the correct grouping?
a. Chloritoid-Pelitic-Hb Hornfels
b. Andalusite-Basic-Px Hornfels
c. Andalusite-Pelitic-AE Hornfels
d. Sphene-Basic-Hb Hornfels
Answer: Andalusite-Pelitic-AE Hornfels
a. Chloritoid-Pelitic-(Hb Hornfels)AE Hornfels
b. (Andalusite-Basic-Px Hornfels)
d. Sphene-Basic-(Hb Hornfels)AE Hornfels
Which among the following is the correct grouping?
a. Augite-QzFeldspathic-Px Hornfels
b. Corondum-Basic-Px Hornfels
c. Lizardite-Pelitic-Hb Hornfels
d. Talc-Basic-Hb Hornfels
Answer: Augite-QzFeldspathic-Px Hornfels
b. Corondum-(Basic)Pelitic-Px Hornfels
c. Lizardite-(Pelitic)Ultrabasic-Hb Hornfels
d. Talc-(Basic)Ultrabasic-Hb Hornfels
Which among the following is the correct grouping?
a. Augite-QzFeldspathic-Px Hornfels
b. Corondum-Basic-Px Hornfels
c. Lizardite-Pelitic-Hb Hornfels
d. Talc-Basic-Hb Hornfels
Answer: Augite-QzFeldspathic-Px Hornfels
b. Corondum-(Basic)Pelitic-Px Hornfels
c. Lizardite-(Pelitic)Ultrabasic-Hb Hornfels
d. Talc-(Basic)Ultrabasic-Hb Hornfels
Which among the following is the incorrect grouping?
a. Idocrase-Calcareous-Hb Hornfels
b. Vesuvianite-Calcareous-AE Hornfels
c. Spinel-Pelitic-Px Hornfels
d. Spinel-Basic-Hb Hornfels
Answer: Spinel-(Basic)Ultrabasic-Hb Hornfels
a. Idocrase-Calcareous-Hb Hornfels
b. Vesuvianite-Calcareous-AE Hornfels
c. Spinel-Pelitic-Px Hornfels
Which among the following is the correct grouping?
a. Wollastonite-Calcareous-AE Hornfels
b. Forsterite-Basic-Hb Hornfels
c. Anorthite-Ultrabasic-Hb Hornfels
d. Chloritoid-Pelitic-AE Hornfels
Answer: Chloritoid-Pelitic-AE Hornfels
a. Wollastonite-Calcareous-(AE Hornfels)Hb and Px Hornfels
b. Forsterite-(Basic)Ultrabasic-Hb Hornfels
c. Anorthite-(Ultrabasic)Calcareous-Hb Hornfels (or Px Hornfels)
Which of the following is the incorrect grouping?
a. Tremolite-Calcareous-AE & Hb Hornfels
b. Augite-QzFeldspathic-Px Hornfels
c. Microcline-QzFeldspathic-All Hornfels
d. Andalusite-Pelitic-All Hornfels
Answer: Microcline-QzFeldspathic-(All Hornfels)AE & Hb Hornfels
a. Tremolite-Calcareous (and Ultrabasic)-AE & Hb Hornfels
b. Augite-QzFeldspathic-Px Hornfels
d. Andalusite-Pelitic-All Hornfels
Anorthosite is what kind of a rock?
a. coarse-grained composed essentially of alkali plus calc-alkali feldspars
b. fine-grained composed essentially of feldspars
c. coarse-grained composed essentially of plagioclase
d. coarse-grained essentially composed of quartz and feldspar
coarse-grained composed essentially of plagioclase
what is a calcium rich rock of magmatic origin called?
a. carbonatite
b. carbonado
c. calciphyre
d. calcilutite
carbonatite
What is an ocellar texture?
a. where all grains are very small
b. where groundmass contains large crystals
c. in which glass shards predominate
d. where platy minerals form radiating groups
where groundmass contains large crystals
What is a greisen?
a. metasomatised granite
b. rock containing glaucophane
c. quartz monzonite
d. migmatitic rock
metasomatised granite
What is the percentage of silica in a granite?
a. more than 90
b. 75-90
c. 75-80
d. 40-90
c. 75-80 (70-77% in some sources)
The rock of which the tombstone of the so-called founder of Kolkata was made is given which name?
a. hollandite
b. charnokite
b. khondalite
c. blanfordite
The rock of which the tombstone of Job Charnock, the founder of Kolkata, was made is called charnokite (any orthopyroxene-bearing quartz-feldspar rock formed at high temperature and pressure)
What kind of rock is a minette?
a. a lamprophyre
b. a serpentinite
c. a granite
d. a basalt
A minette is classified as a lamprophyre. Lamprophyres are a group of small-volume, ultrapotassic igneous rocks characterized by the presence of biotite and/or amphibole, along with other minerals.
Diamonds do not occur in which one of the following rocks?
a. kimberlite
b. lamproite
c. borolanite
d. orangeite
Answer: borolanite (pyroxene-melanite bearing nepheline syenite)
- Lamproite (diamond-bearing, Kimberlite occurs mainly in craton, and lamproite in the margin of craton)
- Orangeite (A kind of kimberlite with phlogopite macrocrysts and microphenocrysts)
What is a tachylite?
a. glassy basalt
b. porphyritic basait
c. tholeiitic basalt
d. variety of gabbro
glassy basalt
A rock which is composed essentially of plagioclase and pyroxene with quartz as accessory is called?
a. eclogite
b. basalt
c. pyroxenite
d. dacite
Basalt
Pegmatite is considered which type of igneous rock?
a. intrusive
b. hypabyssal
c. extrusive
d. effusive
intrusive
Which among the metamorphic facies are observed in igneous intrusions or shallow hydrothermal metamorphism?
Hornfels and Sanidinite
These metamorphic facies are observed in burial metamorphism, at ocean ridges, hotspots, and volcanic arcs.,
Zeolite and Prehnite-Pumpellyite
Critical Zeolite facies minerals, which commonly coexist with quartz, include
analcime, laumontite, heulandite, and wairakite
Although some zeolite minerals occur in the prehnite - pumpellyite facies, ______ and ______ are restricted to the zeolite facies.
laumontite and heulandite
Higher temperature alteration of prehnite and pumpellyite results in the neocrystallization of _____ and _____, two minerals that mark the transition to the higher grade albite - epidote hornfels facies and the greenschist facies
actinolite and epidote
Which metamorphic facies are NOT typically produced by dynamothermal metamorphism under conditions of non - uniform stress, particularly at convergent plate boundaries.
Zeolite, Prehnite-Pumpellyite, Hornfels, and Sanidinite
Where metapelites occur, the greenschist facies can be subdivided into three Barrovian zones:
Lower to Uppermost: Chlorite, Biotite, Garnet
The transition from greenschist to amphibolite facies is marked by an increase in _____, _____, and _____.
hornblende, garnet and anthophyllite
Differentiate Granulite I vs Granulite II in granulite metamorphic facies. What are its distinguishing minerals?
Hydrous minerals hornblende and biotite, but not muscovite, can occur in the lower part of the granulite facies, sometimes referred to as granulite I. The upper part of the granulite facies, sometimes referred to as granulite II, is characterized entirely by anhydrous minerals.
_____ facies rocks are abundant in orogenic fold and thrust belts, where theyrecord regional, moderate temperature/pressure metamorphic conditions at convergent plate boundaries.
Greenschist
This mineral is a common dehydration product of Amphibolite and Granulite metamorphic facies which can be observed in in regional orogenic belts at convergent margins.
Diopside
form in subduction zones where oceanic lithosphere is forced downward to great depths at geologically rapid rates. As cold oceanic lithosphere is dragged downward into Earth ’ s interior it absorbs heat from the surrounding asthenosphere very slowly, reaching great depths while remaining relatively cool.
Blueschists
In the ACF diagram what kind of rock contains 60% [(Al2O3+Fe2O3)-(Na2O+K2O)], 20% [CaO-3.33P2O5], and 20% [FeO + MgO + MnO]?
a. Pelitic
b. Basic
c. Ultrabasic
d. Quartzo-Feldspathic
e. Calcareous
Pelitic
Low C, Increasing A order:
Ultrabasic, Basic, Quartzo-Feldspathic, and Pelitic
High C, None to Low A:
Calcareous
In the CMS diagram, this contains 50% CaO and 50% SiO2.
a.Dolomite
b. Wollastonite
c. Enstatite
d. Diopside
Wollastonite
To be called a dolomite the rock should contain how much
percentage of magnesium?
a. more than 90%
b. 80-85%
c. 60-90%
d. 100%
c. 60-90% (More than 50%)
What was the name of the geologist who first introduced the concept of metamorphic facies?
P. E. Eskola
The texture due to the presence of radiating group of platy minerals with indistinct outlines is known as?
a. idioblastic
b. granoblastic
c.. poliloblastic
d. ocellar
Answer: Poliloblastic
a. Idioblastic: This texture refers to crystals that have well-developed faces and clear outlines
b. Granoblastic: This texture is characterized by equidimensional grains that are interlocking
d. Ocellar: This term typically refers to a texture where larger grains (or “eyes”) are surrounded by finer-grained material
What is metamorphic aureole?
a. end product of metamorphism
b. baking effect on the surfaces of a sandstone
c. zone around an igneous body
d. zone around a metamorphic mineral
zone around an igneous body
A composite rock made up of igneous or igneous-appearing and/or metamorphic minerals is known as what?
a. chorismite
b. orthogneiss
c. injection gneiss
d. migmatite
migmatite
What is a characteristic mineral formed by high grade metamorphism of argillaceous rocks?
a. chlorite
b. sillimanite
c. forsterite
d. periclase
sillimanite
Minerals in diablastic-textured rocks typically show which form?
a. radiating platy
b. acicular or fibrous
c. prismatic
d. euhedra
Diablastic (Decussate) texture is characterized by equigranular, interlocking, and randomly oriented platy, tabular, prismatic, or elongate minerals.
Mineral lineation in metamorphic rocks is caused by:
a. recrystallisation
b. crushing
c. rubbing against each other
d. deformation
deformation
The process of simultaneous dissolution and deposition by which a new mineral of partly or wholly different chemical composition may grow in the body of an old mineral is known as?
metasomatism
What is the sign of uniaxial minerals that are geometrically prolate?
Positive
A process where a magma chamber squeezes out the more mobile liquid into a new chamber and leaving behind a residue of crystals
Filter Pressing
_____________, or iodoquinine sulfate, is a chemical compound whose crystals are dichroic and thus can be used for polarizing light. It was discovered in 1852 by a Bristol surgeon and chemist. One of his pupils found that adding iodine to the urine of a dog that had been fed quinine produced unusual green crystals.
Herapathite
Type of magma that records a progressive decrease in Fe and Mg with increasing SiO2 and alkali concentrations due to crystal settling of ferromagnesian minerals. Commonly occurs in convergent margins.
Calc-alkaline Magmas - produce largely andesites, dacites, rhyolites, and high-alumina Basalts
Magmas enriched in Fe with low to moderate SiO2 due to early and rapid crystallization of MgO and CaO. Common in Ridges, rifts, and some hotspots.
Tholeiitic magmas - produces basalt with little variations
Magmas highly enriched in Na2O and/or K2O and contains extremely diverse compositions of SiO2. Occurs in wide variety of environments
Alkaline Magmas
Magmas are characterized by high concentrations of silicic and basic rocks, with little intermediate rocks, associated with continental rifts. Derived from partial melting of the mantle and the continental crust.
Bimodal magma suites
Rounded masses of radiating crystals that develop from devitrification
Spherulites
What mineral is nicknamed “white snowflakes” that grew within the black, glassy obsidian.
Cristobalite (SiO2)
An igneous texture characterized by a cloudy appearance and cracks.
Perlitic
A rock has 3.5% vesicles, what should be its modifier name?
Vesicle-bearing
A pyroclastic rock that consists largely of solidified ash
Tuff
What does CIPW stand for?
a. Clark, Irving, Powell, Woodward
b. Carter, Ingle, Page, Wells
c. Cross, Iddings, Pirsson, Washington
d. Coleman, Ingersoll, Platt, Whitman
Cross, Iddings, Pirsson, Washington
According to Shand Classification, a rock with 65% dark colored minerals are?
a. Mesocratic
b. Mafic
c. Intermediate
d. Melanocratic
Melanocratic (Intermediate if Ellis Classification)
This aluminum oxide classification has a chemistry makeup: Al2O3 > CaO + Na2O + K2O. Key minerals include muscovite, corondum, topaz, garnet, tourmaline, etc.
Peraluminous rocks
This aluminum oxide classification has a chemistry makeup: Na2O + K2O < Al2O3 < CaO + Na2O + K2O. Key minerals include hornblende, epidote, melilite, biotite, pyroxene.
Metaluminous rocks
This aluminum oxide classification has a chemistry makeup: Al2O3 = Na2O + K2O. Key minerals include: Olivine, opx, and cpx
Subaluminous
IUGS Classification seems to be applicable to all igneous rocks based on modal compositions but there is actually a rule in which IUGS cannot be used to classify certain igneous rocks. What is the rule?
IUGS is only applicable to igneous rocks with >10% felsic and <90% mafic content by volume
In the TAS classification, this rock consists of 6% Alkali and 53% SiO2
Basaltic Trachyandesite (Basaltic Soshonite)
In the TAS classification, this rock consists of 15% Alkali and 60% SiO2
Phonolite
In the TAS classification, this rock consists of 8% Alkali and 45% SiO2
Tephrite/Basanite
All of the following are Cpx except for two which are Opx:
Aegerine, Augite, Diopside, Enstatite, Hypersthene, Omphacite, Spodumene
CPX: Aegerine, Augite, Diopside, Omphacite, Spodumene
OPX: Enstatite, Hypersthene
E-MORB contains ____ REEs and represents ____ degrees of partial melting
Higher; Smaller (10-15%)
These two rocks are signatures of Island arcs
a. Boninite and Adakite
b. Tonalite and Granodiorite
c. Boninite and Trondhjemite
d. Tonalite and Plagiogranite
Tonalite and Plagiogranite (aka Trondhjemite)
It is a fibrous hydrous borate hydroxide of sodium and calcium. It is also called a TV Rock or a Chameleon Rock due to its unusual properties distinct towards transparent crystals.
Ulexite
intrusive rocks with typical granitic composition (quartz and feldspar) but containing only a small portion of potassium feldspar. They have Archean associations where they are believed to be an important component in the growth of continental crust.
Tonalite, Trondhjemite (Plagiogranite), and Granodiorite
Enumerate the time boundaries of Major GTS time divisions
(See internet)
Enumerate the time boundaries of Major GTS time divisions
(See Internet)
This Period is 300 million years ago.
Late Carboniferous/Early Permian
Shallow intrusive rocks that contain >20% Carbonate minerals primarily at continental rifts.
Carbonatites
Mg-rich and volatile rich, porphyritic rocks containing mafic phenocrysts and are associated with kimberlites and continental rift zones
Lamprophyres
K-rich, peralkaline rocks containing pyroxene and olivine minerals enriched in Ba, La, Zr but poor in CO2, and occurs in areas with thickened lithosphere that have experienced earlier plate convergence or rifting episodes.
Lamproites
a.) An Olivine and Orthopyroxene-rich (>90%) rock b.) An Olivine and Clinopyroxene-rich (>90%) rock c.) An Olivine-rich and Intermediate blend of Opx and Cpx (>90%) rocks d.) An olivine-poor (<10%) rock
a.) Harzburgite
b.) Wehrlite
c.) Lherzolite
d.) Websterite
Detrital sedimentary rocks that contain >30% gravel-sized clasts
Gravelstones
Grabau classification for gravelstones
Rudite
Grabau classification for sandstones with negligible amount of mud
Arenite
Grabau classification for sandstones with negligible amount of mud
Arenite
It is the greek name equivalent of Rudite, Arenite, and Lutite
Psephite, Psammite, and Pelite respectively
Alteration type that generates biotite, K-felds, and adularia
Potassic
Alteration type that generates Kaolinite, Smectite, and Illite
Argillic
Alteration type that generates Quartz, Sericite, and Pyrite
Phyllic
Alteration type that generates Chlorite, Actinolite, Epidote, and Tremolite
Propylitic
What is the coordination number for a simple cubic lattice?
In a simple cubic structure, each atom has six immediate neighbors: one above, one below, and four surrounding it in the same layer. Indicating that each atom is directly in contact with six other atoms in its vicinity
What is the coordination number of a body centered cubic structure?
In a body-centered cubic lattice, each atom at the center of the cube is surrounded by eight atoms located at the corners of the cube. This configuration results in a coordination number of 8, meaning each atom is in contact with eight nearest neighbors.
What is the coordination number of a face centered cubic structure?
Each atom at the corners of the cube is surrounded by 12 nearest neighbors: 4 from the same face, and 4 from each of the two adjacent faces above and below.
How many crystal systems are recognized in 3d space
7
Who is the Islamic philosopher whom rejected the idea that metallic elements could be transformed into one another.
Avicenna
Space Group refers to?
a. The geometric pattern of atoms
b. The translational symmetry of a crystal structure
c. The density of a crystal
d. The color of a crystal
The translational symmetry of a crystal structure
What property determines whether the crystal structure is polar or not?
Crystal System
What is the maximum atomic packing factor achievable in unit cells constructed of spheres of only one size? Discuss why.
a. 0.34
b. 0.52
c. 0.74
d. 0.68
For structures formed by spheres of a single size, the densest arrangements are the face-centered cubic (FCC) and hexagonal close-packed (HCP) structures, both of which achieve an APF of approximately 0.74. This means that 74% of the volume in these arrangements is filled with spheres, while the remaining 26% is empty space.
Which of the following is an example of a material with a face-centered cubic structure? Provide other examples as well.
a. NaCl
b. Graphite
c. Diamond
d. Copper
Copper (remember that FCC is common among metals)
What symmetry operation involves changing the signs of the coordinate of each points?
Inversion
What mineralogical text by James Dwight Dana has been continuously revised since its first publication?
Manual of Mineralogy
What work of Pliny the Elder focused on the classification of earths, metals, stones, and gems?
Naturalis Historia (Natural History)
He is considered as the father of modern crystallography.
a. Nicholas Steno
b. J. J. Berzelius
c. R. J. Hauy
d. J. L. Rome de I’Isle
Answer: R. J. Hauy
a. Nicholas Steno (Interfacial Angles and Stratigraphy)
b. J. J. Berzelius (Chemical Nomenclature)
d. J. L. Rome de I’Isle (Later developments of mineralogy and crystallography)
How many possible structure symmetries, called space groups, exist?
230
What type of symmetry operation involves a combination of a rotation and a translation?
a. Reflection
b. Inversion
c. Glide plane
d. Screw axis
Screw axis
What type of crystal defect is characterized by an extra half-plane of atoms?
a. Vacancy
b. Interstitial
c. Edge dislocation
d. Screw dislocation
Edge dislocation
End-centered unit cells only exist in?
a. Cubic system
b. Orthorhombic system
c. Tetragonal system
d. Triclinic system
Orthorhombic system
notation is used to represent the symmetry elements in point groups, plane groups and space groups.
Hermann–Mauguin notation
Which mineral is an example of a biaxial mineral?
a. Quartz
b. Calcite
c. Hornblende
d. Garnet
Answer: Hornblende (Monoclinic)
a. Quartz (Hexagonal)
b. Calcite (Trigonal)
d. Garnet (Isotropic)
What property allows minerals like diamond to display a fire of colors?
a. High refractive index
b. Strong pleochroism
c. Low dispersion
d. High dispersion
Answer: High dispersion - higher dispersion (0.044 for diamond), more efficiency to split white light into its spectral colors.
What impact does a high numerical aperture (N.A.) have on the resolution of a polarizing microscope?
It increases resolution (N.A. is a measure of a microscope objective’s ability to gather light and resolve fine specimen detail)
Which mineral is known as having anomalous interference colors?
a. Tourmaline
b. Beryl
c. Apatite
d. Leucite
Tourmaline (anomalous means cannot be observed in Michel-Levy Chart)
In biaxial positive crystals, which direction corresponds to the acute bisectrix (Bxa)?
a. X direction
b. Y direction
c. Z direction
d. Optic normal direction
Z direction
An interference figure shows yellow interference colors in the center and blue on the concave sides after inserting an accessory plate. What is the optic sign of the mineral?
a. Positive
b. Negative
c. Neutral
d. Indeterminate
Positive
In the staining of carbonates, which mineral does not typically react with alizarin red S?
a. Dolomite
b. Calcite
c. Aragonite
d. Magnesite
Dolomite
Which technique is most effective for evaluating water content in hydrous minerals?
a. X-ray fluorescence
b. Scanning electron microscopy
c. Raman spectroscopy
d. Infrared spectroscopy
Answer: Infrared spectroscopy
a. X-ray fluorescence (elemental composition)
b. Scanning electron microscopy (Higher resolution image of crystal structure)
c. Raman spectroscopy (also evaluates water content but less effective than Infrared)
Which instrument is primarily used to determine the elemental composition of a mineral sample?
a. Scanning Electron Microscope (SEM)
b. X-Ray Fluorescence (XRF)
c. Atomic Absorption Spectrometer (AAS)
d. Mass Spectrometer
X-Ray Fluorescence (XRF)
In a phase diagram, what does miscibility gap refer to?
a. A temperature range where all minerals are solid
b. A region where two minerals coexist in equilibrium
c. A composition range where no single mineral is stable
d. A point where all minerals melt
A composition range where no single mineral is stable
Which of the following minerals is NOT a member of the mica group?
a. Biotite
b. Chlorite
c. Annite
d. Lepidolite
Answer: Chlorite
a. Biotite (Mg-, Fe-rich mica)
c. Annite (Iron Biotite)
d. Lepidolite (Li-bearing mica)
Which of the following is a V-rich mica?
a. Roscoelite
b. Glauconite
c. Annite
d. Phlogopite
Answer: Roscoelite
b. Glauconite (Green Mica)
c. Annite (Iron-end Biotite)
d. Phlogopite (Brown Mica)
Which mineral reacts with quartz to produce albite?
a. Leucite
b. Analcime
c. Pyroxene
d. Nepheline
Nepheline
Which of the following pyroxenes is known for being stable only at high temperatures?
a. Pigeonite
b. Diopside
c. Augite
d. Enstatite
Pigeonite
Which of the following is not a part of the olivine group?
a. Forsterite
b. Larnite
c. Tephroite
d. Jadeite
Jadeite
Which mineral’s name is derived from the Greek word meaning distinct?
a. Galena
b. Enargite
c. Bornite
d. Cinnabar
Enargite
What is the crystallographic system of Sylvite?
Cubic
Which mineral is associated with a television rock appearance?
Ulexite
Which mineral is named after a French mining engineer?
a. Carnotite
b. Wavellite
c. Autunite
d. Erythrite
Carnotite (U-bearing)
What is the largest known gabbroic occurrence on Earth?
a. Columbia River
b. Duluth Complex
c. Yellowstone
d. Idaho Batholith
Duluth Complex
Which igneous rock is especially abundant at hot spots like Yellowstone?
a. Basalt
b. Andesite
c. Rhyolite
d. Granite
Rhyolite
A rock is identified with more than 50% hornblende and less than 40% olivine. How would this rock be classified?
a. Peridotite
b. Pyroxenite
c. Hornblendite
d. Websterite
Hornblendite
Rocks formed by the breakdown and redistribution of pre-existing rock fragments are referred to as?
a. Endogenetic
b. Exogenetic
c. Intrabasinal
d. Orthogenic
Answer: b. Exogenetic
a. Endogenetic (within the Earth)
c. Intrabasinal
d. Orthogenic
What is the Dolomite Problem?
a. Dolomite does not form in modern oceans.
b. Dolomite is unstable under Earth’s surface conditions.
c. Dolomite is only formed in freshwater environments.
d. Dolomite does not contain calcium carbonate.
Dolomite does not form in modern oceans.
According to Folk’s classification, what is a limestone with more carbonate mud than
sparry calcite cement called?
a. Oosparite
b. Micrite
c. Sparite
d. Biosparite
Micrite
The ratio of which isotopes is used to distinguish between continental and mantle
sources?
a. Strontium-87 to Strontium-86
b. Rubidium-85 to Rubidium-87
c. Carbon-12 to Carbon-14
d. Oxygen-16 to Oxygen-18
Answer: Strontium-87 to Strontium-86
C and D are for paleoclimatic conditions
Continental crust have higher 87Sr/86Sr ratios compared to mantle
If you discover a rock with perlite features in an archaeological site, how could this assist
in dating the artifacts found nearby?
a. Use the size of vesicles to determine the rock’s formation period
b. Analyze the mineral content to match with known historical data
c. Estimate the degree of hydration to infer the age of the perlite
d. Assess the rock’s density changes over time
Estimate the degree of hydration to infer the age of the perlite (Perlite is hydrous)
If a rock displays a poikilitic texture, what can be inferred about the crystallization
process?
a. The larger grains crystallized first, followed by smaller grains filling the spaces.
b. The smaller grains crystallized first, before being enclosed by larger grains.
c. All grains crystallized simultaneously, resulting in uniform grain size.
d. The rock experienced metamorphism after initial crystallization.
The smaller grains crystallized first, before being enclosed by larger grains.
What does a trachytic texture suggest about the flow dynamics during the formation of
an igneous rock?
a. The rock experienced minimal flow, resulting in random grain orientations.
b. The rock underwent significant flow, aligning plagioclase grains.
c. The rock formed in a static environment with no flow.
d. The rock’s grains were altered post-formation, unrelated to flow.
The rock underwent significant flow, aligning plagioclase grains
What synthetic process is commonly used to produce corondum gemstones?
Verneuil Process (Flame Fusion)
In optical mineralogy, a test made on polishing relief, which is visually similar to the Becke line test, but different in origin. This line moves towards the softer mineral when the stage is lowered.
Kalb Light Line
Variety of opacitic where there is a secondary rim or corona
Kelyphitic
Intergrowth of plagioclase feldspar in alkali feldspar host
Perthitic
Which part of the microscope is also referred to as the Nicols because it is made up of Nicol prisms?
Lower Polarizer
What type of condenser lens is used for orthoscopic illumination?
Fixed Condenser Lens (all except interference figures are observed)
What type of condenser lens is used for conoscopic illumination?
Auxillary Condenser Lens (Mounted In and Out, for interference figures)
What is the minimum symmetry for Cubic crystal system?
a. 1A4
b. 6A2
c. 3A4
d. 4A3
Answer: 4 three-fold rotation (A2)
Tetragonal - 1A4
Hexagonal - 1A6
Trigonal - 1A3
Orthorhombic - 3A2
Monoclinic - 1A2
Triclinic - None
What is the minimum symmetry for Orthorhombic crystal system?
a. 1A4
b. 3A2
c. 3A4
d. 2A3
Answer: 3 two-fold rotation (A2)
Cubic - 4A3
Tetragonal - 1A4
Hexagonal - 1A6
Trigonal - 1A3
Monoclinic - 1A2
Triclinic - None
The following only have Primitive Bravais Lattice except:
a. Monoclinic
b. Trigonal
c. Triclinic
d. Hexagonal
Answer: Monoclinic - Primitive, Edge-centered
Cubic - Primitive, Face-centered, Body-centered
Tetragonal - Primitive, Face-centered
Orthorhombic - all 4 Bravais Lattice
Hexagonal - Primitive
Trigonal - Primitive
Triclinic - Primitive
Which of the following Bravais Lattice is the cubic system missing?
a. Primitive
b. Edge-centered
c. Face-centered
d. Body-centered
Edge-centered
The orthorhombic system is known to contain all 4 Bravais Lattices. One particular Bravais Lattice: Edge-centered, is present in another crystal system, which is?
a. Cubic
b. Triclinic
c. Trigonal
d. Monoclinic
Answer: Monoclinic - Primitive, Edge-centered
Cubic - Primitive, Face-centered, Body-centered
Tetragonal - Primitive, Face-centered
Orthorhombic - all 4 Bravais Lattice
Hexagonal - Primitive
Trigonal - Primitive
Triclinic - Primitive
Which crystal system has one angle that is not 90°?
Answer: Monoclinic (“Mono-” one, “-cline” angle, incline)
Cubic Bruh, its a cube
Tetragonal (“Tetra-” four, “-gon” side/face, only achieved if all angles are equal (90°) and one axis is not equal to the other 2 creating ONLY 4 identical faces)
Orthorhombic (“Ortho-” 90°, “-rhombus” no axes are equal in length)
Hexagonal - (“Hexa-” six, “-gon” sides/faces, only achieved if all angles are equal (120°) and one axis is not equal to the others creating ONLY 6 identical faces)
Trigonal (“Tri-” three, “-gon” sides/faces, Toblerone-shaped, only achieved if all angles are equal (60°) and one axis is not equal to the others creating ONLY 3 identical faces)
Triclinic - (“Tri-” three, “-cline” angle, incline)
Which crystal system is comparable to the shape of a Toblerone chocolate?
Answer: Trigonal (“Tri-” three, “-gon” sides/faces, Toblerone-shaped, only achieved if all angles are equal (60°) and one axis is not equal to the others creating ONLY 3 identical faces)
Monoclinic (“Mono-” one, “-cline” angle, incline)
Cubic Bruh, its a cube
Tetragonal (“Tetra-” four, “-gon” side/face, only achieved if all angles are equal (90°) and one axis is not equal to the other 2 creating ONLY 4 identical faces)
Orthorhombic (“Ortho-” 90°, “-rhombus” no axes are equal in length)
Hexagonal - (“Hexa-” six, “-gon” sides/faces, only achieved if all angles are equal (120°) and one axis is not equal to the others creating ONLY 6 identical faces)
Triclinic - (“Tri-” three, “-cline” angle, incline)
There are 24 identical faces in the form _____ in the cubic system which combine to give a trapezohedron.
a. {112}
b. {210}
c. {111}
d. {110}
Answer: {112}24 - garnet and leucite
{210}12 - Pentagonal Dodecahedron (Pyritohedron in pyrite)
{111}8 - Octahedron (fluorite)
{110}12 - Dodecahedron (garnet)
The form {110} in the cubic system which combine to give a _____.
a. trapezohedron
b. dodecahedron
c. octahedron
d. pentagonal dodecahedron
Answer: {110}12 - Dodecahedron (garnet)
{112}24 - Trapezohedron (garnet and leucite)
{210}12 - Pentagonal Dodecahedron (Pyritohedron in pyrite)
{111}8 - Octahedron (fluorite)
Pure limestone is composed of calcite but oftentimes it is impure containing _____ and _____. Which can react at T ~500C to form Forsterite.
a. garnet and feldspar
b. quartz and dolomite
c. glauconite and aragonite
d. hematite and quartz
Quartz and Dolomite
Serpentine, which is a metamorphosed Olivine (which contains both Fe and Mg), can only contain very few Fe. The excess Fe released from olivine during alteration to serpentine usually occurs as small grains of _____.
Magnetite (Fe2O3)
The name mica was probably derived from the Latin micare meaning to ____. Stacks of mica flakes are often referred to as “____”
shine; books
Explain why micas are common in granite but rare in its volcanic equivalent called rhyolite?
Magma at the surface of the Earth (= lava) cannot contain much water in solution. Hydrous minerals (like micas) are therefore not common in volcanic rocks but can form in plutonic rocks.
The coexistence of two intergrown phases is commonly visible in hand specimens of slowly cooled alkali feldspars; such intergrowths are known as _____
Perthite
