Parts with gray text probably won't be covered on the exam.

Symmetry

  1. Know all of the 7 crystal systems by heart, including relative axial lengths and angles between axes.
  2. Know by heart all of the symmetry operators involved in the 32 crystal classes: center of symmetry, axes of rotation, mirror planes, and rotary inversion axes.
  3. Given a block model, be able to identify the crystal class while using the crystal class handout.
  4. Be able to plot all symmetry operators and crystal faces on a stereo net, using the appropriate symbols.
  5. Know all of the Bravais lattices, and which lattices belong to which crystal systems.
  6. Know how all of the symmetry operators involved in the 230 space groups work: glide planes and screw axes.
  7. Be able to find mirrors, rotation axes, centers of symmetry, screw axes, and a, b, and c glides, in a crystal structural model, if you are told that they are there.
  8. Be able to pick out the unit cell from a structure model.
  9. Be able to calculate Miller indices from axial intercepts. Be able to assign reasonable Miller indices to simple faces in block models.
  10. Know what a zone axis is.

Bonding and Coordination

  1. Know the basic differences between the various types of chemical bonds: covalent, ionic, metallic, hydrogen, and Van der Waals.
  2. Know the general relationships between ionic radius and charge of a single atom.
  3. Know the regular coordination polyhedra: line, triangle, tetrahedron, octahedron, cube, dodecahedron. Know about other non-regular coordination polyhedra, such as: triangle, square plane, triangular dipyramid, square antiprism, triangular prism, hexagonal prism.
  4. Be able to construct or identify the two types of closest packed arrays of spheres: hexagonal closest packed and cubic closest packed.
  5. In a crystal structure model, be able to identify the coordination numbers of various atoms in the structure, regardless of whether or not the bonds are shown with metal rods.

Mineral Properties

  1. Be able to accurately use all common mineral tests: habit, cleavage, hardness, luster, color, streak, magnetism, dilute HCl, fluorescence, radioactivity, taste, density, hand lens, stereo microscope.
  2. Be able to distinguish between crystal faces and cleavage planes.
  3. Be able to determine something about the crystal symmetry from the arrangement of well-developed cleavage in a crystal.
  4. Be able to identify on sight the common minerals.

Crystal Chemistry

  1. Know the approximate, or at least relative, ionic radii and common coordination numbers of the most common ions in silicate and other oxygen-rich structures: Si, Ti4+, Fe2+, Fe3+, Mn2+, Mg, Ca, Na, K, P, O, OH, F, Cl, S6+.
  2. Understand how simple and coupled substitutions work. Be able to apply substitutions in a known structure such as a pyroxene.
  3. Be able to pick out multi-atom substructures in structure models, especially coordination polyhedra and shared polyhedral elements: corners, edges, and faces.
  4. Given a chemical analysis of a mineral, be able to calculate a structural formula.

Twinning, Exsolution, Inversion, etc.

  1. Know what twinning is and how growth twins differ from transformation twins.
  2. Know the twin laws for common twinning in feldspars: carlsbad, albite, and pericline.
  3. Understand how exsolution in a binary solid solution works: the temperature effect, the solvus, end members in a binary solid solution, and host and lamella relationships.
  4. Know at least three examples of minerals that show exsolution relationships.
  5. Be able to explain the differences between displacive and reconstructive inversion transformations.
  6. Be able to give examples of polymorphs and pseudomorphs.
  7. Be able to give some examples of isostructural compounds.

Silicate Structures

  1. Know the differences between and be able to identify in structure models the different silicate mineral types: nesosilicates, sorosilicates, cyclosilicates, inosilicates, phyllosilicates, and tectosilicates.
  2. Know how silicate chains and sheets connect to their respective octahedreal chains and sheets.
  3. Understand the layer types in 1-, 2-, 3-, and 4-layer sheet structures, and know mineral examples of all of these.
  4. Understand the reasons for varying amounts of extension in tetrahedral chains and sheets.
  5. Understand the stacking vector concept in the common sheet silicates, and be able to explain the various types of vector stacking: 1M, 2M1, 2M2, 3T, 6H, 2O.
  6. Know the P-T stability relationships between the three aluminosilicate polymorphs: kyanite, sillimanite, andalusite.
  7. Know the CaSiO3-MgSiO3-FeSiO3 pyroxene phase diagram, including the approximate composition fields for wollastonite, diopside, augite, hedenbergite, pigeonite, enstatite, and orthoferrosilite and solid solutions.
  8. Know the anorthite-albite-orthoclase phase diagram, and solid solutions in this diagram at low, medium, and high temperatures.

Color in Minerals

  1. Understand the concepts behind the various origins of color in minerals: mineral grain contaminants, conduction band transition, atomic energy level transitions (e.g., d orbital transitions), charge transfer absorption, reflection interference, diffraction, and color centers.
  2. Be able to give examples of minerals that show each color mechanism, and the colors these minerals have.

X-ray Diffraction

  1. Know Bragg's law by heart. Be able to rearrange Bragg's law to solve for any of the variables. Be able to define all of the Bragg's law variables.
  2. Be able to sketch a typical powder X-ray diffraction setup, such as the one we have, and be able to identify and sketch the X-ray tube, detector, sample, X-ray beam, and the theta and 2 theta angles that vary during a scan.
  3. On an indexed X-ray scan be able to identify first, second, third, and higher order diffractions from a single first order diffraction peak.
  4. Understand the origins of the continuum and line spectra generated in an X-ray tube.
  5. Know the equation relating photon energy (E) and wavelength.
  6. Know the equation relating electrical current (A), voltage (V), and power (W).
  7. Know what an absorption edge is and how filters work to reduce the Kβ interference in X-ray diffraction work.

Immersion Oils and Interference Figures

  1. Know the basic refraction equation.
  2. Be able to explain the origin of Becke lines, and why Becke lines become colored near an oil-mineral index match.
  3. Understand the three optical indicatrix types: isotropic, uniaxial, and biaxial.
  4. Be able to assign the proper refractive index designations (n, epsilon, omega, alpha, beta, gamma) to the axes of all three indicatrix types.
  5. Be able to identify these centered optic figures: uniaxial optic axis, biaxial optic axis, flash figure, biaxial BXA with the isogyres remaining in the field of view.
  6. Be able to measure: optic sign, sign of dispersion (biaxial minerals only), the sign of elongation of any elongate grain, and extinction angle on any elongate grain or grain with a parallel set of cleavage cracks.
  7. Be able to quickly find optic axis and flash figures in grains in a randomly oriented grain mount.

17 mineral chemical formulae

  1. Quartz
  2. Albite (a feldspar)
  3. Anorthite (a feldspar)
  4. K-feldspar (a feldspar)
  5. Actinolite (as an example of amphiboles in general)
  6. Muscovite (a mica)
  7. Biotite (a mica)
  8. Diopside (a pyroxene)
  9. Enstatite (a pyroxene)
  10. Garnet (almandine as an example of garnets in general)
  11. Andalusite (an aluminosilicate)
  12. Kyanite (an aluminosilicate)
  13. Sillimanite (an aluminosilicate)
  14. Pyrite
  15. Rutile
  16. Ilmenite
  17. Magnetite
  18. Know common chemical substitutions in feldspars, olivine, amphibolies, micas, pyroxenes, and garnets.

Kurt Hollocher

Geology Department

Union College

Schenectady, NY 12308

U.S.A.