Theme: Mineralogical Crystallography

IMA2014 is proud to help celebrate the International Year of Crystallography with the following sessions covering mineralogical crystallography.

 

Crystallography and its Importance in Applied Mineralogy

Convenors: Prof. Volker Kahlenberg - CAM; Prof. Johan De Villiers

Description:
Crystallography within the field of Mineralogy is not only a discipline that helps us to understand important structural relationships and the crystal chemistry of certain mineral families but it is also of great value when solving problems related to compounds that are of interest for applied mineralogy. The idea of the proposed session is to give scientists from all different fields of applied mineralogy a forum to underline the importance of crystallographic input for the characterization, quantification and optimization of their materials.

 

Diffuse Scattering in Minerals

Convenors: Prof. Florence Porcher; Dr. Ulli Bismayer; Dr. Gopinathan Sankar

Description:
The diffraction pattern of a crystalline compound is not made of Bragg peaks only but, among others, presents also a contribution from diffuse scattering, which comes from chemical and structural disorder as well as from the presence deviations from the ideal periodicity, including nano-structured regions. The evolution of experimental techniques, in particular synchrotron radiation which has opened new frontiers in the study of the structure of matter, as well as of the theoretical approaches to model the diffuse scattering, allows today to extract a significant amount of information from this part of the diffraction pattern via the so called total scattering or pair distribution function (PDF) analysis. This session is devoted to present, analyse and discuss the exploitation of diffuse scattering in the structural study of mineral phases and the recent advances in the application of synchrotron radiation in mineralogy which, with SESAME facility coming into full operation in late 2015, is becoming of easier also for developing countries.

 

Modular Aspects of Mineral Structures

Convenors: Prof. Massimo Nespolo; Prof. Marco Pasero; Prof Sergey Krivovichev

Description:
Modular structures are built by modules (blocks, rods, layers) which differ either in the chemistry or in the crystallographic orientation / position. They include polytypes and OD structures, polysomatic and homologous series, cell-twins, as well as twins and epi/syntaxies. The structure-building principle allows fine tuning of both structure and chemical composition and represents one of the most outstanding mechanisms by which Nature produces a wide range of minerals from a relatively limited number of building blocks. The understanding of the features of these minerals represents a challenge both for the experimental mineralogist and for the theoretician and opens a huge horizon for crystal engineering.

 

Physics, Chemistry and Crystallography of Minerals

Convenors: Dr. Stefan Stöber - Institut für Geowissenschaften und Geographie; Mr. Christoph Berthold

Description:
The session is dedicated to present applications of modern solid state physics and chemistry to minerals and materials synthesized after the example of nature. It includes studies of the materials properties (crystal structure, phase transitions, physical properties etc.) and thus developed structure-property relationships at ambient conditions, but also at low and high temperatures (as well as at high pressures). Since 2014 is the International Year of Crystallography, the session welcomes especially contributions which highlight the interplay and the connections between crystallography and mineralogy.

 

Relationships Between Surface and Bulk Structure of Layered Minerals

Convenors: Prof. Maria Brigatti; Mr. Giovanni Valdre; Mr. Stephen Guggenheim

Description:
Crystal chemistry and structure of layer minerals was widely investigated in numerous contributions, as demonstrated in several works devoted to this topic Particular attention was devoted to the following aspects: 1) structural variations, as a function of intensive and extensive parameters; 2) modelling of layer structure modifications following from composition; 3) chemical and stacking order-disorder; 4) interstratifications and intercalations; 5) crystallographic aspects of polytypism and twinning. Most of these studies were however devoted to mineral bulk structure, leaving aspects related to surface and to the uppermost layers close to surface less detailed. Earth scientists generally investigate the bulk structure of minerals by X-ray diffraction or neutron diffraction. However, the knowledge of chemistry, structure, and microtopography of mineral surfaces is a key step for understanding mineral interaction with the surrounding environment. Chemical and physical properties, particularly for layer silicates, mainly depend on the atomic structure of the uppermost layers, which may differ from the bulk structure following reconstruction or relaxation processes.

Keynote Presenter:  Chiara Elmi
Keynote Presentation:  Sodian Muscovite-2M1:  Crystal chemistry and surface features

 

Recent progress in the crystal chemistry of minerals: Systematizing mineral properties and behaviour

Convenors: Prof. Georges Calas, Prof. Frank Hawthorne

Description:
During the last few years, there has been considerable progress in understanding mineral structure using diffraction, spectroscopy and computational techniques. The session will focus on structural characterization of minerals and the rationalization/understanding of crystal structures via topological description. It will also include the geological implications of a better knowledge of the structure of "real" minerals, including non-stoichiometry and the structure of non-stoichiometric phases, crystal chemistry of minor and trace components, nature and location of defects and the nature of solid solutions." Such a session will be coordinated with sessions on modularity and on HP/HT.

 

General Session - Mineralogical Crystallography 

Convenors: Prof. Johan de Villiers

Description:
This is a general session under the theme of Mineralogical crystallography for submission of abstracts that do not conform with other sessions under this theme.