Acta Musei Moraviae

Corundum-bearing pegmatite from Pokojovice near Třebíč, Czech Republic

The Pokojovice corundum-bearing pegmatite is found in the varied group of Moravian Moldanubicum. It forms a discordant dike, up to 2 m thick, penetrating amphibolite with thin layers of calcite marble, and skarn-like rocks. The pegmatite is composed of three different units:

1. Pyroxene pegmatite (K-feldspar + Fe-diopside + plagioclase + titanite ± quartz ± amphibole ± biotite).
2. Biotite pegmatite (K-fefdspar + biotite + plagioclase).
3. Corundum pegmatite (K-feldspar + corundum + plagioclase + biotite ± muscovite ± tourmaline).

The geological position, as well as the mineral and chemical composition of pegmatite and the surrounding rocks are described. The paper also discusses conditions of the corundum formation.