MINERALOGY AND ROCK CONSTITUENTS WITH LABORATORY 1

Module LABORATORY OF MINERALOGY AND ROCK CONSTITUENTS

EXPECTED LEARNING OUTCOMES

The course aims to provide students with adequate knowledge of the rock-forming minerals and their properties. It also aims to train students in the application of this knowledge. A focus will be made to practical techniques and procedures for identifying the most common minerals. Skills: become familiar with the polarizing microscope and understand how it works. Learn how to read and interpret mineral optical charts. Understand the fundamental analytical techniques for identifying the chemical and physical characteristics of minerals. Recognize morphological elements, including symmetry elements configuration, from observation of three-dimensional crystal models. Be able to make thin section observations in order to recognize the main rocks forming minerals.

Furthermore, concerning the Dublin Descriptors, this course contributes to the acquisition of the following transversal skills:

Knowledge and understanding:

-    inductive and deductive reasoning skills

-    ability to schematize a natural phenomenon in terms of scalar and vector physical quantities

-    ability to set up and solve a problem using appropriate spatial relationships between recognizable geometric elements in a three-dimensional model representing an ideal mineral, using graphical, analytical or numerical methods

-    ability to recognize simple geometric elements in natural mineral samples and/or three-dimensional models, and use scientific instruments to carry out simple experimental tests

-    ability to understand the physical characteristics of rock forming minerals.

Ability to apply knowledge:

-    ability to apply acquired knowledge to the description of minerals at mesoscopic and microscopic scales with the aid of a polarizing microscope, using the scientific method rigorously

-    ability to identify elements of symmetry in three-dimensional models;

-    ability to represent mineral compositions on binary and ternary diagrams.

Independent judgement:

- Critical thinking skills

-    ability to identify the most appropriate methods for critically analyzing, interpreting and processing experimental data

-    ability to assess the accuracy of measurements and the sensitivity and selectivity of the techniques used

Communication skills:

-    ability to present scientific topics orally and/or in writing with appropriate linguistic precision and to illustrate their rationale and results.

Learning skills:

-    ability to read, understand and critically analyze scientific texts and topics with a particular focus on mineralogy

-    ability to independently learn new scientific topics in the field of Mineralogy that are necessary for further studies.

Information for students with disabilities and/or Specific Learning Difficulties (SLDs):

In order to ensure equal opportunities and comply with current legislation, interested students may request a personal interview to plan any compensatory and/or dispensatory measures based on educational objectives and specific needs. You can also contact Prof. Giorgio De Guidi, the CInAP (Centre for Active and Participatory Integration – Services for Disabilities and/or Specific Learning Difficulties) reference teacher in our department.

Teaching will be carried out through participatory lessons and exercises. These will include the use of a polarizing microscope to study minerals in thin sections, three-dimensional models representing the various crystal systems and multimedia technologies, such as immersive virtual 3D models.

Basic knowledge of mathematics, chemistry and physics.

Compulsory as per the degree (Corso di Laurea) regulations.

COURSE CONTENT

1) Crystal groups and crystal systems, including translations, rotations and inversions, symmetry operators (center, axes and planes), and their recognition on three-dimensional models. Also covered are Hauy's law and the indexing of directions and faces in various crystal systems, and the identification of symmetry classes. Introduction to stereographic projections.

2) Shape, habit, color, cleavage traces, possible birefringence, surface alterations, possible twinning, fractures, streak and reactions with diluted hydrochloric acid. Estimation of hardness, specific weight and density.

3) Interactions between crystalline solids and polarized light; birefringence; the polarized light microscope (its parts and how it works); polaroid filters; Snell's law; the refractive index; an overview of optical phenomena and the laws of geometric optics.

4) An overview of creating thin rock sections and making microscopic observations in parallel light with a polarizer only (color, pleochroism, cleavage traces, relief, shape, size, alterations and inclusions), and with crossed polarizers (interference colors, extinction type, extinction angles, possible compositional zoning and twinning). Observations in convergent light will also be covered (interference figures and optical behavior).

5) Introduction to X-rays and their applications in Mineralogy

1. Mineralogia - Klein C. - Zanichelli Editore, 2004.

2. Mineralogia 1 - (Carobbi) Fondamenti di cristallografia e ottica cristallografica - Mazzi F. e Bernardini G.P. - USES Ed. Scientifiche Firenze, 1971.

3. Guide to thin section microscopy - M.M. Raith, P. Raase, J. Reinhardt, 2nd edition, 2012.

4. Introduzione ai minerali che costituiscono le rocce - William A. Deer, Robert A. Howie, Jack Zussman, G. Della Ventura, E. Paris – Zanichelli ed. 1994

An oral examination is aimed at ascertaining the knowledge of the topics covered in the course, along with: 1) a practical test aimed at the mesoscopic identification of the most common minerals in rocks by evaluating morphological characteristics and physical properties present in the sample by hand; 2) a practical test under a polarized light optical microscope aimed at the identification of the main minerals that constitute the igneous, sedimentary, and metamorphic rocks from the Department's teaching collection and the accurate and appropriate presentation of the conclusions based on the observations made; 3) a practical test aimed at the recognition of elements of symmetry (inversion centers, planes of symmetry, rotation axes) in 3D models to trace the relative group and crystal system, and the indexing of faces in 3D models.

In order to ensure equal opportunities and comply with current legislation, interested students may request a personal interview to plan any compensatory and/or dispensatory measures based on educational objectives and specific needs. In such a case, please get in touch with Prof. Giorgio De Guidi, the CInAP representative for our department (Centre for Active and Participatory Integration – Services for Disabilities and/or Specific Learning Difficulties).

Recognise elements of symmetry by examining a three-dimensional model visually.

Recognise and describe optical indicatrices.

Recognise optically isotropic and anisotropic minerals with a light polarised microscope.

Estimate the relief of minerals using the Becke line method.

Obtain the pleochroism pattern through observations under a polarising microscope.

Measure extinction angles relevant to the microscopic recognition of minerals.

Determine the optical sign of minerals.

Recognise the main minerals in thin sections.