the Domanín Formation. In Moravia, moldavite occurrences are restricted to an area roughly bounded by the towns of Třebíč, Znojmo and Brno. The colour of Moravian moldavites usually differs from their Bohemian counterparts, as it tends to be brownish. Taking into account the number of pieces found, Moravian localities are considerably less productive than the Bohemian ones; however, the average weight of the moldavites found is much higher. The oldest (primary) moldavite-bearing sediments lie between Slavice and Třebíč. The majority of other localities in southern Moravia are associated with sediments of Miocene as well as Pleistocene rivers that flowed across this area more or less to the southeast, similar to the present streams of Jihlava, Oslava and Jevišovka. Properties The chemical formula of moldavite is SiO2(+Al2O3). Its properties are similar to those of other types of glass, and reported Mohs hardness varies from 5.5 to 7. Moldavite can be transparent or translucent with a mossy green color, with swirls and bubbles accentuating its mossy appearance. Moldavites can be distinguished from most green glass imitations by observing their worm-like schlieren. Use Moldavites were discovered by prehistoric people in the Czech Republic and Austria and were used to make flaked tools. Some of the worked moldavites date to the Aurignacian period of the Upper Paleolithic, approximately 43,000 to 26,000 years before the present. In the modern world, moldavites are often used, rough or cut, as semi-precious stones in jewelry. They have purported metaphysical qualities and are often used in crystal healing. Presentation There is the Moldavite Museum in Český Krumlov, Czech Republic. The Moldavite Association was established in Ljubljana, Slovenia in 2014. The association researches, exhibits and promotes moldavites and other tektites around the world and has member geologists from more than 30 countries worldwide. Gallery References J. Baier: Zur Herkunft und Bedeutung der Ries-Auswurfprodukte für den Impakt-Mechanismus. - Jber. Mitt. oberrhein. geol. Ver., N. F. 91, 9-29, 2009. J. Baier: Die Auswurfprodukte des Ries-Impakts, Deutschland, in Documenta Naturae, Vol. 162, München, 2007. Further reading Milan PRCHAL "60 years on the green wave". (Robert Jelinek, Admir Mesic Eds). Der Konterfei 072, Vienna, 2021. External links Moldavite Museum in Český Krumlov Gemstones Glass in nature Impact event minerals