Geols. 422. Crystal Chemistry of the Rock Forming Minerals

This course is offered in alternate years in the Spring Semester.

Class Hours: Lectures are currently scheduled at Mon. from 1-3:30 and Wed.
from 1-2:40.

Text: Introduction to Mineral Sciences by A. Putnis, Cambridge University Press.

Prerequisites: GeolS 220 (Introduction to Mineralogy) or its equivalent. It is assumed
that you have a general (although not necessarily a working) knowledge of
symmetry, crystallography, and elementary mineralogy. 

1. Introduction, Bonding characteristics: Ionic bonding, Born theory.

2. Born theory (cont.), Covalent bonds: Schrodinger atom, orbital orientations,
hybrid bonds.

3. Covalent bonds: Hybrid bonds (cont.), van der Waals bonds, Metallic bonds:
Band theory.

4. Bond lengths and polyhedral distortions: Pauling's rules, non-saturated anions,
cation-cation repulsions, crystal field theory.

5. Crystal field theory (cont.), CFSE, ligand field strength.

6. Crystal field theory (cont.), low-spin, high-spin, calculated CFSE, Jahn-Teller
effects.

7. Physical properties of solids: Optical properties related to crystal structure,
Piezoelectric effects.

8. Physical properties of solids: Cleavage, magnetic properties.

9. True metal structures: Closest packing, body centered cubic, alloys (AuAg,
AuCu), ordered and substitutional solid solutions.

10. Consequences of order/disorder relations, Superstructures, some diffraction
effects, anti-phase domains, Interstitial alloy structures.

11. Structures with intermediate metal and covalent bonds (sulfides), Covalent
compounds, diamond and derivative structures, evidence of covalency, stuffed
derivative structures (ex., spinels).

12. Exam 1: Cover topics 1-10.

13. Return of exams, Ionic compounds: Types based on bond strength, AX and AX2
structures, polarization in AX2 type layer structures.

14. Gibbsite and brucite: The hydrogen bond, hydrogen vs hydroxyl bond
distinctions.

15. Types of solid state transformations: Displacive, reconstructive, dilatational,
rotational disorder, substitutional disorder and bond type.

16. Classification of silicate structures, the nature of the Si-O bond, use of closest
packing to solve early structures; Silicate structures: Orthosilicates.

17. Silicate Structure: Orthosilicates: Other olivine types structures. The
aluminosilicates-Kyanite, Andalusite and Sillimanite; Silicate Structures:
Sorosilicates and Belov's Chapter B of the silicate story.

18. Silicate Structures: Single infinite chains, pyroxenes, structural aspects,
quadrilateral pyroxenes, compositional trends.

19. Silicate Structures: non-quadrilateral pyroxenes, exsolution and solid state
transformations.

20. Silicate Structures: Double chains, amphiboles, compared to pyroxenes,
structural aspects, order/disorder, phase relations.

21. Silicate Structures: Al content in amphiboles; Pyroxenoids and different chain
geometries, crystal chemistry, Biopyriboles-different chain widths.

22. Exam 2: Covering topics 11-20.

23. Return of exams, layer silicates, classification and terminology, X-ray
identification of clay minerals.

24. Silicate Structures: Layer silicates, mica polytypes.

25. Silicate Structures: Layer silicates, serpentines, polytypes, kaolins.

26. Silicate Structures: Layer silicates, distortions, T-O misfit and its consequences
in micas and serpentines (modulated layer silicates of the 1:1 type).

27. Silicate Structures: Layer silicates, modulated layer silicates of the 2:1 type,
palygorskite/sepiolite.

28. Silicate Structures: Feldspars, structural aspects, classification, K feldspars, Al/Si
order/disorder, microcline twinning.

29. Silicate Structures: Plagioclase feldspars, structural aspects and immiscibilities,
Al/Si order/disorder, satellite reflections.

30. Silicate Structure: Plagioclase feldspars, interpretations of domains, exsolution.