Rocks are part of the Earth’s crust, usually composed of several types of minerals, and their composition cannot be expressed by a chemical formula. On closer examination, however, they offer a wondrous spectacle. The colourful world of petrology is presented in the exhibition “Stones under the Microscope”, which was prepared at the Regional Museum in Olomouc by Martin Kováček, a graduate of Environmental Geology, together with Tomáš Lehotský from the Department of Geology; both also work at the Regional Museum. The exhibition is on display until 7 January 2024.
“To the casual observer, the rocks may appear monotonous, grey, dead and utterly uninteresting. An experienced geologist can use the minerals visible to the eye as a guide as to what kind of rock it is. But the most accurate way to determine this is under a microscope. Even an ordinary stone can hide a whole colourful universe of minerals that cannot be seen by the naked eye,” said Kováček, curator of the exhibition.
In the Mendel Hall of the museum, all basic types of rocks are exhibited – igneous or magmatic (i.e., intrusive and extrusive), metamorphic, and sedimentary rocks. “From the igneous rocks, visitors can compare a sample and its microscopic specimen from gabbro, granite, pegmatite, and basalt; from the metamorphic rocks, a clast or gneiss will certainly catch the eye; and from the sedimentary rocks, for example, a Tertiary biogenic limestone full of microfossils. These are the basic rock types found in our territory. The stalactite section, with characteristic concentric incremental layers of calcite, is also interesting,” added Lehotský.
The exhibition also has an educational character. Thanks to its self-study programme, it is suitable for families with children and school excursions. With the help of a simple interactive application, they can try working with the microscope. “Among the highlights we have prepared for visitors are the now historic Meopta polarizing microscope and the goniometer for measuring axial angles in crystallography. The exhibition is complemented by large-format prints of microscopic slides, which have an artistic character,” said Kováček, inviting visitors to come and see the most interesting things of the exhibition for themselves.