Moldavite – Chlum, Czech Republic
 The formation of Moldavites is explained as follows:
 The approximately 1.5 km-diameter meteorite entered the Earth's atmosphere at about 20 km/s, forming the crater now known as the Nördlinger Ries. Immediately before impact, the soil was extremely compacted; under high pressure and temperature, the rock melted and was ejected at several kilometers per second, partially in a plasma state. The shallow angle of impact played a role in this. Interactions and degassing took place in the ejected material, which explain the differing elemental contents and typical shapes.[1] During the flight, the material cooled rapidly and thus solidified into a glassy (amorphous) form. The moldavites are therefore pieces of glass; they were transported between 250 and 450 kilometers above the dense atmospheric layers and mostly fell back to Earth in what is now the Czech Republic. (Source: Wikipedia)