Mgr. Jakub Kopecký Plášil, Ph.D.
Crystallography and mineralogy are mutually tightly connected scientific disciplines. The quick development of mineralogy in the end of 19th and the beginning of 20th century was followed by the upswing of its younger sister crystallography. Until the discovery of the diffraction of X-rays by the atomic structure of crystalline solids by Walther Friedrich, Paul Knipping and Max von Laue, the crystal were studied only by optical goniometers and about their inner arrangements there were just poor ideas. Nowadays, mineralogical crystallography benefits from all modern diffraction techniques, including diffraction of electrons by means of transmission electron microscopes. These techniques are used for structure determination of minerals and natural phases and their reactions (phase transitions).
The group of mineralogical crystallography is focused on the structure and chemistry determination of environmentally important minerals. They comprise naturally occurring oxysalts hydrates that contain either heavy-metal elements, such as Bi, Pb or Sb, or other dangerous elements (U, Th). Among other phases of interest are also sulphosalts, namely those containing Tl, and the products of their weathering. The group of mineralogical crystallography deals with the solution and refinement of complicated crystal structures, namely twins and modulated structures. Last, but not least, the group is for a long time involved in structure determination and description of new minerals. Those provide quite often uniquely new, unprecedented structures that stimulate further studies in order to understand their structural and physical properties and possible applications.