Is moldavite a meteorite?
No. Moldavite is green natural glass formed from Earth rock melted by an impact in southern Germany about 14.8 million years ago.
Moldavite is often sold as a 'meteorite gemstone', but it is not a meteorite.
What it is. Moldavite is a type of tektite, a natural glass. It is bottle-green to olive-green and translucent, often with a wrinkled or sculpted surface caused by natural etching in the ground.
How it formed. About 14.8 million years ago, an asteroid perhaps a kilometre or more across struck what is now southern Germany, forming the Nördlinger Ries crater, about 24 kilometres wide, and the smaller nearby Steinheim crater. The impact melted surface sediments, rich in sand, and flung molten droplets eastwards. They cooled into glass and fell across what is now the Czech Republic, Austria and parts of Germany, roughly 200 to 450 kilometres from the crater.
How it is recognised. Genuine moldavite contains elongated bubbles and tiny curved threads of pure silica glass called lechatelierite, which form only at very high temperatures. Its colour is usually muted green, never very bright or uniform. Its density is about 2.3 to 2.4 grams per cubic centimetre.
Fakes. Moldavite is popular in jewellery, so many imitations are made from bottle or industrial glass. These are often too bright, too clear, too uniform or too cheap.
Myths. Moldavite is sometimes promoted with claims of special powers. These have no scientific basis.
Moldavite is a fascinating impact product, telling the story of a major impact in Europe, and it is a reminder that impacts can turn Earth's own rocks into new materials.