MINERALOGY AND OPTICAL MINERALOGY
Learning outcomes of the course unit
The course objectives are to learn about:
1) Basics of morphological and lattice crystallography
2) the physical properties of minerals useful to their identification
3) systematics of the most common minerals in the rocks and in the environment
4) basics in otical mineralogy and microscopy techniques
The purpose of the course is to provide basic knowledge on the chemical and physical properties of minerals and the interaction between minerals and the environment.
Classes in Chemistry and Mathematics
basic knowledge in chemistry and physics
Course contents summary
Mineralogy studies minerals that are the building bricks of rocks. The mineralogy is preliminary to courses on Earth Sciencesbecause of the interactions between minerals and man. The aim of the course is to provide the basics on the chemical and physical properties of minerals and to gain acquaintance with the techniques of optical mineralogy, looking forward to applications in petrology classes. Minerals and environment will be a major focus in the course
The mineralogy studies the minerals that are the building blocks of rocks. The mineralogy is preparatory courses of Geological Sciences as minerals are the basic units for the study of Earth sciences and because of the multiple interactions between minerals and man.
Definition of mineral. Minerals in the environment, resources, and environmental risks.
Part 1. The minerals: what they are made of
Mineralogical crystallography: patterns bi-and tri-dimensional. Transaltional symmetry and crystalline systems. Morphological crystallography.
Steno and Hauy laws. Miller indices.
Indexing of faces and edges. Elements of morphological symmetry
of crystals. The 32 point groups. The
stereographic projection: projection and recognition of the symmetry elements and determination of the point symmetry in crystals.
Part 2. Chemical and Physical Properties: a path to identification.
Scalar and vectorial properties and relations with the symmetry of the mineral: thermal expansion, compressibility, speed of light in mineral, hardness and magnetization. X-ray diffraction and mineral identification.
Chemical properties: the main elements of the Earth's crust. Ionic radius and coordination polyhedra. The tetrahedron SiO4. Pauling's rules. Types and examples of polymorphism in minerals.
Isomorphism. Phase diagrams of mineralogical interest, for one, two three components.
Part 3. Minerals in nature and the environment
Systematic mineralogy: main structural features,
chemical and physical properties of the most common mineral groups. It will also be examined the distribution of minerals in the environment and the interaction with humans. Silica phases. Feldspars: chemistry and order-disorder transformations. Feldspathoids. Inosilicates: amphibole and pyroxene. Phyllosilicates: derivation of structural types, mica and clay minerals. Nesosilicate: olivine and garnet. Overview of epidotes, tourmaline, anhydrous silicates of Al, zircon.
Non silicates: the groups CO32-, SO42-, PO43-(carbonates, sulfates and phosphates) and main differences with the silicates. Oxides: compact cubic and hexagonal packings. Outline of sulphides and mantle minerals.
Part 4: optical mineralogy: properties of light, refractive index, Snell equation. Optical indicator definition and relationships with symmetry and crystallographic axes. Birefringence, pleochroism, interference figure. Observations in microscopy with parallel and crossed polarizers, and with convergent light.
Definition of minerals. Minerals in the earth and environment, natural and synthetic.
Part 1. Minerals: what are they made of
Mineralogical crystallography: two-and three-dimensional patterns. Translational symmetry
and crystalline systems. Morphological crystallography. Stensen and Hauy laws. Parametric axes and Miller indices.
Indexing of faces and edges. Elements of symmetry and morphology
of crystals. The 32 point groups. The
stereographic projection: projection of the elements of
symmetry and determination of the point symmetry in ideal crystals.
Part 2: Chemical and physical properties: how to identify minerals
Scalar, vector and tensor properties and relations with the symmetry of the mineral: thermal expansion, compressibility, speed of light, and magnetization. X-ray diffraction and mineral identification: powder diffraction and interpretation of the relative diffraction.
Chemical properties: the main elements of the earth's crust. Ionic radius and coordination polyhedra. The SiO44- tetrahedron. The Pauling rules. Polymorphism and isomorphism in minerals.
Phase diagrams in mineralogy.Optical mineralogy, extinction angle, Becke line, optic sign, birefringence, pleochroism. Practical determination of optical properties in minerals
Part 3: Minerals in nature and environment
Systematic Mineralogy: main structural features,
chemical and physical properties of the mineral families. The silica minerals. Feldspars: chemistry, and order-disorder transformations. Feldspatoids. Inosilicates: amphibole and pyroxene. Phyllosilicates: derivation of structural types; mica and clay minerals. Orthosilicates: olivine and garnet. Other silicates: epidote, tourmaline, anhydrous silicates of Al, zircon.
Non silicates: the CO32-, SO42-, PO43- groups(carbonates, sulfates and phosphates) and main differences with silicate minerals. Oxides: cubic and hexagonal compact packings. The spinels. Basics on sulphides. The mantle minerals.
Klein Mineralogia, Zanichelli
Dyar et al Mineralogy and optical mineralogy, Mineralogical society of america
Philippot Earth meterials Cambridge university press
Wenk Mineralogy Cambridge university press
Klein C. (2004) Mineralogia, Zanichelli, Bologna
Wenk H.R., Bulakh A. (2004) Minerals , their constitution and origin, Cambridge University press, CambridgeDyar et al Mineralogy and optical mineralogy (2008), Mineralogical society of america Philippot (2016) Earth meterials Cambridge university press
Teaching methods: The course will be divided into lectures on basic topics, aimed at defining a general theoretical framework and in lectures, always frontal, of an applicative nature focused on the presentation and discussion of mineralogical problems. The lessons will be both theoretical and practical, with special emphasis on the recognition of symmetries with stereographic projection and the learning of basic optical microscopy techniques.
lessons, class and individual demonstrations
Assessment methods and criteria
The exam is divided into three parts, which can be carried out, on the same day or on separate dates (within the year). The final vole comes from the overall results of the exam, none of the three parts gives an independent vote.
1) stereographic projection of a crystal model (preliminary to the continuation of the examination). During the course a test on sterographic projection is planned.
2) oral exam on the subjects of the course;
3) optical determination on a mineral in thin section, to be carried out at the end of the exam.
oral exam, with previous test on stereographic projection and on optical properties of a mineral in thin section
the slides of the course will be uploaded on elly, as well as the texts of all the practical demonstrations carried out in class and other teaching material
frequency, although not mandatory, is highly recommended.