Moldavite is green, natural glasses that are 15 million years ago the impact of a large meteorite ( Ries event) originated in what is now Bavaria and most of them come down in the Czech Republic. Such formed by a meteorite impact and transported over long distances glasses are commonly called tektites, their discovery areas are referred to as stray fields. Of the four known worldwide Tektite stray fields the lost territory of the Moldavite is the so-called Central European strewn field.
The Moldavite are named (Czech Republic) after the main excavation site at the upper course of the river Vltava river in Southern Bohemia. In addition, Moldavite also be found in Moravia. Specimens from Bohemia are mostly bottle green and transparent. Moravian Moldavite, however, are darker than the Bohemian, their color is olive green to brown, they are often used in the ground state as gemstones.
Chance of Moldavite were also found in the area around Eger in western Bohemia, in the Waldviertel ( Austria ) and in the Lausitz ( Germany ). These findings represent small, independent from the big discovery areas in South Bohemia and Moravia stray fields
By Wolfgang Gentner (1971 ) has been demonstrated by determining the age of the potassium - argon method that Moldavite and the so-called Ries event have the same age, that is 15 million years. Therefore, it was likely that the moldavites incurred in the event. After the prairie Saxon deposits of the Upper Freshwater Molasse (OSM ) as a starting material by Günther Graup et al. (1981 ) have been geochemically identified, confirmations followed by further work ( cf. John Baier 2007), which solidified the relationship with the Ries event.
After today's presentation of the process from running as follows:
The diameter around 1,500 meters large meteorite occurred with about 70,000 km / h in the Earth's atmosphere, flanked by a diameter approximately 150 meters great companion. The pieces struck almost unabated one on the earth's surface and formed two large craters, which are now referred to as the Ries and Steinheim Basin. Logging was meteorites and the earth beneath it extremely compacted. Under high pressures and temperatures to melt the rocks and was centrifuged for up to 25 times the speed of sound. During the flight, the material cooled and solidified into glass particles. The Moldavite have been between 250 and 450 km far flung and largely fallen to the ground in what is now the Czech Republic.
Chemical composition: 80% SiO 2; 10% Al2O3; 3 % K2O; 2% FeO; 2% MgO; 1.5% CaO; 0.5 % Na2O; 0.5 % TiO2