2018/2019

2019/2020

DM270

GEO/06 (MINERALOGY)

DEPARTMENT OF EARTH AND ENVIRONMENTAL SCIENCES

GEOLOGICAL SCIENCES

PERCORSO COMUNE

2°

1st semester (01/10/2019 - 15/01/2020)

12

120 lesson hours

Italian

ORAL TEST

DOMENEGHETTI MARIA CHIARA (titolare) - 12 ECTS

Students need to have already followed and acquired the notions of the courses of the I year, in particular Chemistry and Physics.

The aim of the course is to teach students: i) the role of minerals as fundamental components of the litosphere; ii) the basic notions about symmetry in the crystalline state; iii) how identify and study a mineral on the basis of its crystallographic, physical (in particular the interaction with light and X-ray) and crystal-chemical (relations between lattice and chemical bonds, isomorphysim and polimorphysim) properties. These notions will be then used for the description and classification of the most important minerals.

Lectures: (6 CFU) What is a mineral. Crystalline and amorphous states. The symmetry of crystals. Fundamentals of geometrical crystallography: the first crystallographic laws (constancy of interfacial angles, Hauy's law, Bravais's law); symmetry operations and their combinations: crystal systems and point groups, (hkl) Miller indices and stereographic projection. Fundamentals of structural crystallography: unit cell; Bravais lattices; screw axes and glide planes; space groups. Fundamentals of crystal-chemistry: ionic radius and coordination polyhedra. Isomorphysm and its interpretation on the basis of the atomic substitutions in the crystal-structure. Polimorphysm and stability fields of the phases. Physical properties of minerals: density, hardness, fracture and tenacity, electrical and magnetic properties. Symmetry of the physical properties and Neumann’s principle. X-ray diffraction for the identification of mineral crystalline phases. Bragg’s law. X-ray powder diffraction (Debye camera and X-ray powder diffractometer) for mineral identification by using databases. Notes on X-ray single-crystal diffraction method. Chemical analysis (fundamentals of X-ray fluorescence and electron microprobe). Introduction to Optical Mineralogy: the polarizing microscope; birefringence, optical indicatrix. Orthoscopic observations: interference colours and extinction conditions. Conoscopic observations: interference figures. Systematic Mineralogy: silicates, native elements, halides, sulfides, oxides, carbonates, sulfates and phosphates.
Practicals: (6 CFU) Mineral identification: by sight, by interpreting powder X-ray diffraction patterns, by observing thin sections of the most important rock-forming minerals using a polarizing light microscope. Two or three tutors will help students during practicals.

The course includes lectures and practicals.The lectures, consisting in presentations in Power Point and explanations on the board and using educational material, can be integrated by specific seminars. The practicals concerning the stereographic projections of models of minerals are carried out together with the teacher and the tutors in the classroom; those concerning the study at the optical polarized microscope are carried out with the teacher and the tutors in the Laboratory of optical microscopy. Lectures followed by visits to the Mineralogy Museum and the X-ray Diffraction Laboratory are also planned.

All the teaching material will be available on Kiro platform.

CAROBBI: Vol. 1°: Fondamenti di cristallografia e ottica cristallografica (a cura di F. Mazzi e G.P. Bernardini); Vol. 2°: Cristallografia chimica e mineralogia speciale (a cura di C. Cipriani e C. Garavelli). Edizioni USES

DYAR, GUNTER, TASA: Mineralogy and Optical Mineralogy, Mineralogical Society of America

PECCERILLO & PERUGINI: Introduzione alla Petrografia Ottica, Morlacchi Editore

CORNELIS KLEIN: Mineralogia. Edizioni Zanichelli

One or more tutors will help students during practicals and for the preparation of the final exam. Since the first week of the course practicals will be done allowing the teacher to evaluate the degree of students learning. At the end of the first month of lessons and practicals students will be evaluated through a written test. It will be a stereographic projection of a mineral model belonging to the holohedral class of monoclinic, orthorhombic, tetragonal, trigo-exagonal and cubic systems, already examined during the practicals. Students will be evaluated also through a second written test after the practicals of optical mineralogy. It will consist in describing the main minerals identified at the polarizing microscope in the thin section of a rock, already examined during the practicals. At the end of the course, in January, the teacher will be available with students for further discussion and clarification on lectures and practicals. The final exam is an oral test on the content of all lectures and practicals and will take into account the results of the previous written test. The final exam includes the identification of a mineral sample by sight. The tutors will help students in the preparation of the final exam. Student who does not pass the written test or cannot take it will be admitted in any case to the final exam.

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