Hexagonal system
    Monoclinic system
    Miller indicies
    Axial ratio
    Pole of a crystal face
    Inversional symmetry
    Rotational symmetry

Explain the following terms:

    silicates
    carbonates
    isostructure
    polymorph
    solid solution
    exsolution
    hardness
    fluorescence
    coordination number
    Z number
    crystal habit
    piezoelectricity
    thermoluminescence
    isotope

True or False:

  1.Polarized light is weaker (shorter wave amplitude) than non-polarized
    light
  2.It is impossible to have a total refraction when light goes from denser
    media to looser media
  3.Any material has at least one index of refraction
  4.All minerals have index of refraction larger than 1
  5.The optical relief of a mineral can have a negative value
  6.If a mineral has larger optical relief, it would also have higher index
    of refraction
  7.The higher the optical relief, the more clear the boundary of mineral.
  8.The optical relief of a mineral is not a changible feature.
  9.A monoclinic crystal has one optic axis.
 10.Optic axis is defined as a direction along which the light passes with
    the highest speed.
 11.An anisotropic mineral always spits a incoming light into two
    polarized light of different speed.
 12.The two polarized light inside an isotropic mineral vibrates along
    directions perpendicular to each other.
 13.When the two polarized lights in an anisotropic mineral align their
    directions conformably with those of the upper and lower polarizers of
    the microscope, the mineral goes into extinction.
 14.An anisotropic mineral extinct twice with one full rotation of the
    microscope stage.
 15.An isotropic mineral maintain extinction at all position under cross
    polarizer because the two lights inside the mineral always run parallel
    to the directions of the upper and lower polarizer.
 16.When the two lights emerges from the mineral, they interfere each
    other and create interference pattern.
 17.We can see double image of an object through an Iceland Spar because
    calcite has very high birefringence.
 18.There is one and only one direction in a calcite crystal along which
    only one image can be observed.
 19.When a polarized light passes through a polarizer at an angle of not 0°
    neither 90°, it will not be affected by the polarizer.
 20.The total path difference of two lights created by a mineral affects the
    order of interference color.
 21.The standard thickness of a mineral/rock thin section is 30Å
 22.The thicker the thin section, the lower order the interference color
    becomes.
 23.Optic positive minerals has higher optical relief than optic negative
    minerals
 24.An anisotropic mineral has two or three values of birefringence.
 25.Interference color of a mineral can help to indicate the
    crystallographic orientation of the mineral
 26.The optic axis of an orthorhombic mineral is its c axis.
 27.The best way to identify an isotropic mineral is to measure its index of
    refraction.
 28.A thin section cut incline to the c-axis of a hexgonal mineral would
    show two indices of refraction
 29.It is possible for several minerals have the same birefringence
 30.
 

About silica:

  1.How does SiO2 fit into the structure of silicate which is based on
    SiO4?
  2.Name three polymorphs of quartz affected by variation of pressure.
  3.Describe the following mineral properties of quartz
        crystal system and crystal class
        cleavage
        hardness
        color
        interference color
        luster
        density
  4.What is the characteristic crystal form of high-quartz
  5.Name three microcrystalline varieties of silica
  6.What is the chemical formula of opal?
  7.What makes some opal have brilliant play of color?
  8.Describe two environments in which silica can crystallize.

About feldspars:

  1.Name the six plagioclases
  2.Which two crystal systems are most feldspars in?
  3.Name the common cations of all feldspars
  4.Name the major cations of different feldspars
  5.Name the 3 common K-feldspars and describe their stability with
    respect to temperature
  6.Explain the following terms
        alkaline feldspar
        perthite
  7.Describe the following properties of feldspars
        cleavage
        hardness
        color
        interference color
        density
        luster
        twinning
  8.Explain how can we observe three or more cleavages on a feldspar?
    (from which orientation should we see the crystal? what would we
    see?)
  9.How would feldspars respond to weathering?
 10.What is the nature of "striation" usually observed on plagioclase?
 

Review the following questoins:

    Describe the T layer in the phyllosilicate structure
    Describe the O layer in the phyllosilicate structure
    What is the compositional difference between the T layer and the O
    layer?
    Describe the structure of the following phyllosilicates:
        Muscovite
        Kaolinite
        Chlorite
    How does kaolinite differ from serpentine?
    Name three clay minerals.
    Name the following true micas
        K rich mica
        Li rich mica
        Na rich mica
        Ca rich mica
        Mg rich mica
        mica contains K, Fe and Mg
    Clay minerals tends to adsorb ions dissolved in water. Explain why do
    clays have this property but micas do not.
    When we heat up clays, most water escapes at temperature lower than
    200ºC. But a small amount of water is not released until the
    temperature becomes higher than 500ºC. Explain this feature.
    How would micas react to weathering?
    Why is there no clay minerals of igneous or metamorphic origin?
    How is the silicon tetrahedron chain structure different between
    pyroxenes and amphiboles?
    Explain why is there K in amphiboles but not in pyroxenes?
    Explain the cleavage difference between pyroxenes and amphiboles.
    Which two crystal systems do most inosilicates belong to?
    Name major compositional end members in pyroxene group
    Name major compositional end members in amphibole group
    Why is the reason, in terms of chemical composition, that augite and
    hornblende are usually used to represent pyroxene and amphibole?
    Name two inosilicates of igneous origin
    Name two inosilicates of metamorphic origin
    How would most inosilicates react to weathering condition?
 
 

The final test will include the following new questions and all questions of
previous tests.

    What is the value of x and y in Six Oy for nesosilicate, sorosilicates
    and cyclosilicates?
    Describe the normal chemical composition of olivine
    Name the garnet that is rich in Fe; rich in Ca; and rich in Mg.
    Name one mineral in sorosilicates.
    Name one mineral in cyclosilicates
    Sketch the T-P diagram for polymorphs andalusite, kyanite and
    sillimanite.
    Name the Mg rich olivine, garnet, pyroxene and mica. What is the
    common occurrence of these minerals?
 

4. Carbon has two naturally occurring polymorphs.

a. Name them (5 pts.)

b. Describe the differences in their chemical bonding (10 pts)

c. Explain how these differences contribute to different physical properties. (10 pts.)
 
 

1. Give the correct chemical formula for each of the following minerals. (20 pts)

 a. hematite
               k. barite
 b. rutile
               l. smithsonite
 c. biotite
               m. fluorite
 d. chalcopyrite
               n. gypsum
 e. diopside
               o. galena
 f. serpentine
               p. kaolinite
 g. forsterite
               q. enstatite
 h. magnetite
               r. rhodochrosite
 i. tremolite
               s. sphalerite
 j. halite
               t. ilmenite

2. Name the polymorphs for each of the compositions listed. The number in parenthesis beside
each formula is the number of naturally occurring polymorphs. (15 pts)

a. FeS2(2)

b. SiO2 (5, not counting high-low forms)

c. Al2SiO5 (3)

d. C (2)

e. KAlSi3O8 (3)

3. Describe changes in the nature of tetrahedral sharing and of the arrangement of octahedra and
higher-order polyhedra in the minerals found on the discontinuous side of Bowen's reaction
series. Your answer should include the nature of the cations that occupy the various polyhedra in
the different minerals. (20 pts)

4. Name the six crystal systems and list the relations between axial lengths and interaxial angles
for each. (20 pts)

5. Define or explain the following terms: (20 pts)

a. Unit cell

b. Center of symmetry

c. T-O-T or 2:1 phyllosilicate

d. Polymerization
 

7. Explain the structural control on the physical properties listed for each of the following
minerals. (15 pts)

a. Hardness of diamond

b. Cleavage of muscovite

c. Difference in cleavage angles for augite vs. hornblende

d. Hardness of talc

e. Lack of cleavage in quartz

8. What is the title of your textbook? What are the names of the authors of your textbook? (10 pts)

9. Describe the difference between a reconstructive and a displacive phase transformation and
give one example of each. (10 pts.)

15. Discuss compositional variations (e.g., between end members) and describe substitutions of
the major cations in the following mineral groups :

    feldspars
    pyroxenes
    amphiboles
    olivines
    garnets

(you should be generally familiar with all of these examples and know the end-member chemical
formuli).

16. Select the components that best describe the compositional systems containing the above
minerals, aluminosilicates, silica minerals, and/or carbonates and plot their end member
compositions on simplified binary, ternary, or quaternary projections (molar basis). Note that the
system required (and the components too) will depend on which mineral groups you choose to
consider.

17. Discuss the structural classification system for silicate minerals (based on combinations of
[SiO4]-4 tetrahedra); list the subgroups and give at least one mineral example (with chemical
formula) for each (cf. KH, p. 214-216, Ch. 13).

18. Precisely, what is a solid solution? Discuss the three main types of solid solution and
provide mineral examples for each (KH, pp. 233-236):

    substitutional
    omission (or defect)
    interstitial

19. Describe substitutional solid solutions in terms of structural, P, T effects. This is best done
for a specific mineral group (e.g., plagioclases, pyroxenes, olivines). Explain immiscibility and
when/why it occurs - again with respect to specific minerals (cf. KH, ch. 4, 5, & 13).

24. Discuss how mineral physical properties may be determined or controlled by crystal
structure and/or chemical composition; give specific mineral examples for each (KH, ch. 4):

    hardness
    cleavage
    melting point
    density (specific gravity)
    tenacity
 

 Review questions - Optical Mineralogy (refer to N = Nesse)

The following are examples of the kinds of questions that you should be able to answer readily.
However, it is unlikely that the quiz will have questions exactly like those given below.

1. What is the relation between velocity, wavelength, and frequency for light?

2. How does white light differ from monochromatic light?

3. What is Snell's law and why is it useful? Explain with detailed drawings.

4. What is dispersion? Sketch this effect for both white and monochromatic light passing through
a crystal prism.

5. Explain polarization and provide two examples of how light can be polarized.

6. Become familiar with the parts of a petrographic microscope and identify them on a drawing.
Explain the function of each. What is the basic difference between orthoscopic and conoscopic
observation?

7. Define refractive index.

8. Explain why Becke lines form (using drawings) and show how they are used to determine
relative refractive indices.

11. Explain isotropic and anisotropic. What is the relation between these properties and crystal
structure? Give at least 3 examples of materials with each property.

12. For uniaxial crystals, define ordinary and extraordinary rays, and explain how they originate.

15. Define optic sign in terms of both light velocity and refractive index.

17. Define extinction and provide drawings to explain this phenomenon.

18. Define retardation (optically speaking) and explain its relation to (a) phase difference and
interference color, (b) thickness (length of optical path), and (c) refractive indices. What is the
retardation for isotropic minerals?

19. Define birefringence. How would you use the color chart to estimate birefringence in an
mineral in a typical thin section?

20. List the crystallographic classes corresponding to isotropic, uniaxial, and biaxial materials.
Give mineral examples for each.

22. Explain what uniaxial interference figures are, how they are observed, and draw optic axis
and flash figures for both uniaxial negative and positive crystals.

23. Define the following terms and provide sketches where appropriate:

    isochromes
    isogyres
    pleochroism
    first order red
    melatrope
    sign of elongation
    length-fast and length-slow
 

31. Explain pleochroism.
 

2. a) What are the general structural formulae for olivines, pyroxenes, amphiboles and micas. (5 marks)

(b) For each mineral type explain what cation sites are in these structures and what cations occupy A
those sites. (4 marks)
(c) Draw out the pyroxene and amphibole quadrilaterals and explain which binaries show solid solution
and exsolution. (4 marks)
(d) How are the silicate tetrahedra linked in the olivine, pyroxene, amphibole and mica structures? (4
marks)
(e) Explain how the cleavage angle reflect the structure of pyroxenes, amphiboles and micas. (4 marks)

(f) What crystal system (cubic, orthorhombic etc.) does each mineral have? (4 marks)

3. (a) What are Pauling's Rules? (10 marks)
(b) Give examples of how these rules are obeyed in the structures of minerals.
(5 marks) (c) Under what circumstances do mineral structures ignore Pauling's rules ? (2 marks).
(d) Predict the stable ion states of the following atoms from their electronic configurations: Ca (atomic
number 20), F (atomic number 9). (note, write out the electronic configurations. (3 marks)
(e)Using Pauling's rules, predict the structure of CaF2 (flourite) [Hint: Ca is in eightfold coordination].
(5 marks)

4. (a) Explain, using drawings, the structures and chemical relationships of the phyllosilicates. In
particular, describe how the octahedral and tetrahedral layers are stacked in the structures of kaolinite,
muscovite and chlorite. (15 marks)
(b) What is a 2:1 vs 1:1 structure? (3 marks)
(c) Why do phyllosilicates have such perfect cleavage. (2 marks)
(d) Why is talc so slippery? (3 marks)
(e) Name two important clay minerals. (2 marks)
 

3. (25) Compare and contrast the silica polymorphs and the feldspars. Include the chemistry,
structure, and major physical properties for each and how to "create" the feldspars given SiO2 as a
starting material.

4. (25) Compare and contrast the micas, amphiboles, and pyroxenes. Include the chemistry, structure,
and major physical properties for each and how they are similar and differ. Base your answer on the
polymerization of the chains and their stacking.

5. (22) List 22 mineral names and associated chemical formulas. For extra credit, continue the list
using SILICATES ONLY (N.B., you cannot reuse any of the minerals from the "list of 22" and
although you get one extra credit point for each correct mineral-formula pair, you will get a point taken
off for incorrect pairs).

(10) 3. Some clay minerals and some sulfate minerals have the property of reversible
hydration with accompaning volume expansion (during hydration) or volume decrease (during
dehydration). Briefly describe (i.e., give names and chemical formulae) the specific minerals
with this property. Where appropriate, give chemical reactions for the process.

a. Clay Minerals:

b. Sulfate minerals:

(5) 5.a. Draw a ternary composition diagram illustrating the compositions of the major
feldspar minerals. Label the diagram with the names and chemical formulae of the feldspar
end- members. Show the stability fields of plagioclase and the alkali-feldspars as well as any
miscibility gaps in the system.

(5) 6.a. Give the formulae of the following pyroxene group minerals:
 

Diopside: ____________________________

Hedenbergite: ____________________________

Enstatite: ____________________________

Ferrosilite: ____________________________

Aegerine: ____________________________
 

(5) b. Draw the pyroxene quadrilateral. Label the quadrilateral with the names and formulae of the
end-members. Show the composition fields for high-Ca clinopyroxene, pigeonite and orthopyroxene.

(5) 7.a. Write the general formula for the amphibole group minerals. Identify the coordination
numbers of the different sites and list the principal cations and anions that can occupy each
site.
 

(3) b. The primary occurrence of the amphibole tremolite (Ca2Mg5Si8O22(OH)2) is in
metamorphosed siliceous dolomites. White a balanced chemical reaction for the formation of tremolite
in this paragenesis.

(2) c. List two silicate minerals, by name and chemical formula, that may coesist with tremolite in a
marble.
 
 

(10) 9. Describe the types of rocks (in as much detail as possible) that you would expect to find
the following minerals in:

a. Tridymite:

b. High sanidine:

c. Pigeonite:

d. Wollastonite:

e. Glaucophane:

f. Pyrope:

g. Chrysotile:

h. Dolomite:

i. Anhydrite:

j. Staurolite:
 
 

(3) 10.a. Write the general formulae for the dioctahedral and trioctahedral micas.

(4) b. Give the names and chemical formulae of the two most common micas (hint: one is dioctahedral
and the other is trioctahedral).

(3) c. Explain how you would distinguish between the micas paragonite and phlogopite in thin section.