SIG #5
Special Interest Group
on Mineral and Inorganic Crystallography
of the European Crystallographic Association
Promotors:
Giovanni Ferraris, Torino, Italy
Dmitry Pushcharovsky, Moscow, Russia
Proponents:
five ECA councillours
Leonid A. Aslanov, Moscow, Russia
Giovanni Ferraris, Torino, Italy
Alajos Kalman, Budapest, Hungary
Boris Kamenar, Zagreb, Croatia
Jan Kroon, Utrecht, The Netherlands
Introduction:
A Special Interest Group (SIG) on Mineralogical Crystallography (renamed Mineral and Inorganic Crystallography in August 2008) is proposed under the auspices of the European Crystallographic Association (ECA).
Modern Mineralogy is focussed on the fine-scale characterization of the structure and properties of minerals and related compounds, thus being essentially a Geo-material Science.
Although the number of newly characterised mineral species is low when compared to that of small molecules, the capability of their characterization is rapidly improving, and presently allows the understanding of very fine-scale details with are crucial to model physical and chemical properties. In particular, crystallographic methods are a fundamental tool for mineral characterization, and can provide constraints for interpreting the results of other techniques and a basis for a reliable modelling of mineral behaviour.
These models are particularly important as they provide extrapolation to intensive conditions (P, T, fO2, XH2O, bulk composition) which cannot be experimentally verified by characterization of natural material and/or the products of syntheses under controlled conditions. Rock samples coming from the deep interior of the Earth are sporadically available, and cannot represent the possible geological situations. For instance, a sample blasted out from 250 km in a kimberlite pipe in Lesoto (South Africa) represents the deepest available rock, whereas the deepest drilling in Kola Peninsula (Russia) could achieve “only” the level of 12.2 km. Uplifting geological processes (and erosion) brought to surface few metamorphic rocks from (perhaps) 100 km; however, they most probably re-equilibrated during uplift. Within the last few decades extraterrestrial (lunar, martian and interstellar) material became also available, and will be increasingly accessible for mineralogical studies.
In this respect, mineralogists are particularly interested in the development of high-pressure/high-temperature (crystallographic) techniques, which allow simulation of the matter in the interior of the Earth and in extraterrestial conditions. The development and availability of intense- and micro-beam radiation sources (synchrotron radiation) also is opening a new era for characterizing micrometric samples and for the physics and chemistry of minerals, in that it allows in situ determination of (very rapid) cation-ordering processes and phase transitions even on very small crystals or on powdered material. The combination of structural data with the new information from spectroscopies based on synchrotron radiation and (pulsed) neutron sources is also giving extremely promising results. To sum up, the experimental and theoretical problems to be faced by mineralogists, physicists and chemists of minerals span from synthesis and crystal growth to the characterization of the structure and properties, through modelling and development of new methods. For the study of minerals, all crystallographic methods are fundamental tools, from diffraction (X-rays, neutrons, electrons) to microscopy and spectroscopy, from mathematical to physical and crystal-chemical aspects of the crystalline solid state. In particular, powerful methods for the solution of very complex structures from poorly crystalline materials, and for the improvement of the accuracy and the precision of the refinement’s results would be important. That follows from the fact that most of the challenging aspects of modern crystallography are present in minerals, such as:
a) Complicate crystal-chemistry due to the presence of isomorphous substitutions and the
absence of discrete units (molecules); minerals are actually infinite arrays of atoms.
b) Atomic order/disorder at the long- and short-range level which reflect the conditions
experienced by the host rock and may be used to accurately model thermodynamics and
kinetics of the geological processes.
c) Real structures with defects and modulation, resulting, together with b), from deviations from
thermodynamic equilibrium.
d) Structural modularity (polytypism, polysomatism).
e) Phase transitions.
f) Low crystallinity and disordered materials.
Programme
The proposed SIG shall focus in particular on:
1. Development and application of theoretical and experimental aspects of the crystal-
chemistry of minerals and related inorganic structures (including solving, modelling
and predicting crystal structures and their properties).
2. Development and application of theoretical and experimental methods (particularly in the
fields of diffraction, spectroscopy, microscopy, crystal growth and symmetry) for
characterising average and real aspects of this type of structures, also as a function of
thermodynamically relevant parameters such as temperature, hydrostatic and non-hydrostatic
pressure, electric and magnetic fields, oxygen and sulphur fugacities, and water activity.
3. Formulation and definition of the terms and language specific of the field, including the
systematic of minerals and related materials.
4. Preparation and availability of databases and computer programs.
5. Exchange of scientific and teaching information.
6. Organisation of local and international workshops, lecture courses, symposia, etc., with
particular reference to the ECM meetings.
7. The topics to be covered by the SIG on Mineralogical Crystallography shall include
everything dealing with experimental charge densities and related theoretical calculations as
far as related to or applicable to Mineralogical Crystallography.
RULES
The following list of members of the SIG of Mineralogical Crystallography is far from including all the European mineralogists involved with crystallography. The aim of the promoters has been to obtain the assent of a representative group of scientists who, in different European countries, can serve as a first reference for the activities of the European Crystallographic Association in the field of mineralogy and inorganic structures. After approval of the SIG, the membership of the SIG is intended open to all European crystallographers active in the field of mineralogy. It is intention of the promoters to have a meeting of the Founding members and other interested crystallographers either in Glasgow during IUCr-18 or (latest time) in Nancy during the next ECM. In this meeting more formal rules should be established and officers of the SIG (chairman, vice-chairman, secretary) should be formally elected. Till that time, the promoters shall act as contact persons with ECA (G. Ferraris, chairman; D. Pushcharovsky, vice-chairman).
FOUNDING MEMBERS
Giovanni Ferraris, Torino, Italy
Dmitry Pushcharovsky, Moscow, Russia
Thomas Armbruster, Bern, Switzerland
Leonid A. Aslanov, Moscow, Russia
Maria Franca Brigatti, Modena, Italy
Georges Calas, Paris, France
Michael Czank, Kiel, Germany
Martin Dove, Cambridge, U.K.
Slavomil Durovic, Bratislava, Slovak Rep.
Matthias Gottschalk, Potsdam, Germany
Bernard Grobety, Fribourg, Switzerland
Jiri Hybler, Praha, Czech Republic
Paul Keller, Stuttgart, Germany
Natasha Khisina, Moscow, Russia
Martin Kunz, ETH Zuerich, Switzerland
Gyuri Ilinca, Bucharest, Romania
Ole Johnsen, Copenhagen, Denmark
Claude Lecomte, Nancy, France
Friedrich Liebau, Kiel, Germany
Marcello Mellini, Siena, Italy
Stefano Merlino, Pisa, Italy
Roberta Oberti, Pavia, Italy
Artem R. Oganov, London, U.K.
Peter Paufler, Dresden, Germany
Andrew Putnis, Muenster, Germany
Surendra K. Saxena, Uppsala, Sweden
Roman Skala, Praha, Czech Rep.
Elena V. Sokolova, Moscow, Russia
Ekkehart Tillmanns, Wien, Austria
Vadim S. Urusov, Moscow, Russia
Zdenek Weiss, Ostrava-Poruba, Czech Rep.
Pier Francesco Zanazzi, Perugia, Italia