OVERVIEW

Petrography is a discipline describing the Earth rocks: this theoric and practical class provides the elements of igneous, sedimentary and metamorphic petrogenesis, with particular concern to textures and microtextures as they control the performance and the weathering of stones. This class is particularly devoted to cultural heritage as for the analysis of materials relevant to the art history, and for investigation and prevention of stone weathering.

AIMS AND CONTENT

LEARNING OUTCOMES

This class aims at giving the instruments to identify and classify the stones, and to correlate the petrographc analysis with the corresponding technical properties, in order to develop a previsional skill on stone durability.

This will be achieved by lessons, exercises in laboratory and outdoor surveys on monuments and buildings.

AIMS AND LEARNING OUTCOMES

The teaching provides elements of igneous, sedimentary and metamorphic petrogenesis. Having acquired the tools to use the genetic criteria in distinguishing the three rock groups, the program aims at explaining and demonstrating the classification diagrams for the correct and sound nomenclature of rocks and stones. Besides, the commercil nomenclature is compared. The analyis and comprehension of the sedimentary process gives the opportunity of drawing the comparison between rocks exposed at the Earth surface and stone buildings, affected by the same agents.

The exercises on the collection of rocks aims at demonstrating, make understood and to apply the steps of a rock analysis. The integration of the different steps leads to a stone denomination based on robust scientifc diagrams.

A further learning outcome, specific for the cultural heritage is the comprehension of the significance of technical properties  (mechanical, thermic) of stones. Hence, based on the capacity of identfying and evidencing the textural and microabric of rocks, the aims of this section of the class is to connect the petrographic analysis with the corresponding technical properties, in order to develop a previsional skill on the durability of stones. Exercises in the laboratory and in outdoor surveys are tools of the teaching.

PREREQUISITES

In order to get the most out of this class, having attended to Mineralogy applied to Cultural Heritage is strongly suggested, in particular for the mineral systematics (theoric part) and mineral identification  (Theory and exercises).

TEACHING METHODS

Front lessons in the classroom. Front lessons are supported by power point presentations and thematic websites.

Exercises. Practical exercises are based on demostrative rock analyses and discussion on the specimens of the didactic rock collection at Distav. Rock samples are discussed B2B and, if necessary, with the aid of a 3D projector. In the final part of the teaching a demostration at the Laboratory of Scanning Electron Microscopy and / or a technical survey on Genoa building, and / or a technical survey to the Staglieno Monumental Cemetery is included.

The indoor exercises are kept in a dedicated classroom, with microscopes and specific lightning. The pupils are asked to come with a 10x magnification lens and a steel blade to carry out the scratch test (relative microhardness).

SYLLABUS/CONTENT

Origin of igneous, sedimentary and metamorphic rocks. Principles of classification of igneous, sedimentary and metamorphic rocks.
Methods of macroscopic identifications; highlights on other methods. Technical properties of rocks: Physical pproperties (specific weight, volume weight, heap weight, real and apparent porosity, gelivity, imbibition coefficient, thermal conductivity, thermal dilatation, fire resistance). Mechanical properties (compressive strength, tensile strength, flexural strength, impact resistance, hardness, microhardness, workability).

Defects in ornamental stones: color, pigmentation and color stability. weathering and durability.
For each property the relationships with mineral composition and rock fabric will be describes, together with the product test of the reference normative, also with examples on commercial stones.
 

RECOMMENDED READING/BIBLIOGRAPHY

L. MORBIDELLI, Le rocce e i loro costituenti. Bardi Ed. 2014

E.M. WINKLER, Stone in architecture. Springler Verlag, Berlin, 1994

Normative CEN e UNI

Siegesmund S, Snethlage R. (eds) 2011. Stone in Architecture, Properties, Durability Fourth edition, Springer, DOI 10.1007/978-3-642-14475-2

The power point presentations of lessons are availbale on Aulaweb for download.

TEACHERS AND EXAM BOARD

Exam Board

LAURA GAGGERO (President)

ROBERTO CABELLA

SIMONA SCRIVANO

LESSONS

LESSONS START

Lessons will start from 4 March 2019. For lessons start and timetable go to the following link: http://www.distav.unige.it/ccsbenicultura/orario-lezioni

Class schedule

PETROGRAPHY FOR THE CULTURAL HERITAGE

EXAMS

EXAM DESCRIPTION

The examination is an oral test. Questions on the teaching topics are the bulòk of the examination. Secondly, the comprehension of a thematic book chapter or scientific article assigned by the teacher will be verified by the compilation of a power point presentation that will be discussed.

ASSESSMENT METHODS

The examination is an oral test, aimed at verifying the appropriate application of rock classification criteria. Should the need to verify also the skill in identifying the rock components arise, a stone sample would be proposed to the pupil for discussion.

In addition, the critical reading of a book chapter or scientific article on petrographic topics, also in english language, has to be transposed into a power point presentation. The examination is carried out by two enrolled teachers ( or by one enrolled and  one expert in the subject  accredited by board of the teachers LM11). The average length of the examination is 30 minutes.

Exam schedule

FURTHER INFORMATION

Regular frequency is strongly recommended. The course includes laboratory exercises and technical visits to selected destinations (monuments / laboratories / museums / quarries).