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Moldavite (Czech: Vltavín) is an olive-green or dull greenish vitreous substance possibly formed by a meteorite impact. It is one kind of tektite. It was named by Armand Dufrénoy for the town of Moldauthein (Czech: Týn nad Vltavou) in Bohemia (the Czech Republic), where it occurs. It is sometimes cut and polished as an ornamental stone under the name of pseudo-chrysolite.
Moldavite's bottle-green glass colour led to its being commonly called Bouteillen-stein, and at one time it was regarded as an artificial product, but this view is opposed to the fact that no remains of glassworks are found in the neighbourhood of its occurrence; moreover, pieces of the substance are widely distributed in Middle to Upper Miocene and younger fluvial clays and gravelly sands in Bohemia and Moravia.
In 1900, F. E. Suess pointed out that the gravel-size moldavites exhibited curious pittings and wrinkles on the surface, which could not be due to the action of water, but resembled the characteristic markings on many meteorites. Boldly attributing the material to a cosmic origin, he regarded moldavites as a special type of meteorite for which he proposed the name of tektite. However, for a long time, it was generally believed to be a variety of obsidian. Because of their difficult fusibility, extremely low water content, and its chemical composition, the current overwhelming consensus among earth scientists is that moldavites were formed 15 million years ago during the impact of a giant meteorite in present-day Nördlinger Ries. Splatters of material that was melted by the impact cooled while they were actually airborne and most fell in central Bohemia—traversed by Vltava river (German: Moldau). Currently, moldavites have been found in area that includes southern Bohemia, western Moravia, the Cheb Basin (northwest Bohemia), Lusatia (Germany), and Waldviertel (Austria). Isotope analysis of samples of moldavites have shown a beryllium-10 isotope composition similar to the composition of Australasian tektites (Australites)and Ivory Coast tektites (Ivorites). Their similarity in beryllium-10 isotope composition indicates that moldavites, Australites, and Ivorites consist of near surface and loosely consolidated terrestrial sediments melted by hypervelocity impacts.
The total amount of Moldavite scattered around the world is estimated at 275 tons. There are now only four moldavite mines that are in full operation in the Czech Republic. It is predicted that in less than ten years from now[when?] commercial Moldavite mining will come to an end. After this time, there will be virtually no appreciable amount of gem-grade Moldavite left in the ground.
There are typically two grades of moldavite: high quality, often referred to as museum grade, and regular grade. Museum and regular grade moldavite can be told apart by the way they look: The regular grade pieces are usually darker and more saturated in their green colour, and the surface is seen as closely spaced pitting or weathering. This type sometimes appears to have been broken apart from a larger chunk.
The museum grade has a distinct fern-like pattern and is much more translucent than the regular grade. There is usually a fairly big difference in the price between the two. The museum grade "flower bursts" are much more prized by the connoisseur. High-quality moldavite stones are often used in hand-crafted jewellery and thus enter the market away from mainstream jewellery fashions, more centred around art and craft, and as such have gained an almost cult status.
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- Trnka, M.; Houzar, S. (2002). "Moldavites: a review PDF". Bulletin of the Czech Geological Survey 77 (4): 283–302.
- Serefiddin, F.; Herzog, G. F.; Koeberl, C. (2007). "Beryllium-10 concentrations of tektites from the Ivory Coast and from Central Europe: Evidence for near-surface residence of precursor materials". Geochimica et Cosmochimica Acta 71 (6): 1574–1582.
External sources 
|Wikisource has the text of the 1911 Encyclopædia Britannica article Moldavite.|
- 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. ISBN 978-3-86544-162-1