Tektite type whose name is derived from the Moldau (Vltava) river in the Czech Republic where the first pieces were identified. The vast majority of moldavites originate from the Czech Republic where they are mined. Moldavites are generally translucent with extensive etching, and forest green to olive green in color. However, there can be a wide range of opacity, texture and color. For example Moravian moldavites are opaque and dark brown, Lusatian moldavites are smooth, translucent and bright green, and moldavites from Brusna are a pale green with a white frosted and deeply etched appearance.
Moldavites formed about 14.808 ± 0.038 million years ago (middle Miocene epoch) when what is hypothesized to be a binary asteroid impacted the sand-rich surface layer of what is now Germany with such force that the larger 1.5 km wide mass formed the ~24 km Nördlinger Ries rampart crater and the smaller 0.15 km mass created the 3.8 km diameter Steinheim crater. The molten ejecta from the Nördlinger Ries impact cooled as it flew as far as ~450 km from the crater. As the tektites were subsequently covered in soil, water and/or gravel over the millions of years, then underwent various types of etching and erosion processes often unique to the area where they landed thus leading to the delicately figured and deeply etched Besenice moldavites in one type of soil and the rounded and smooth Lusatian moldavites found in gravel pits in Germany. Moldavites have purported to be found in Austria and Poland. The figuring and etching of moldavites is diagnostic of their find location and moldavite experts can identify their location strictly by visual clues.
Moldavites can be distinguished from fakes created using green bottle glass and often peddled on eBay by observing their trapped air bubbles and worm-like inclusions of lechatelierite. Moldavites are NEVER red, light blue or yellow. Fakes are cast glass and do not have the sharp etching most often found in real moldavites.