Moldavite is a forest green, olive green or blue greenish vitreous silica projectile rock formed by a meteorite impact in southern Germany that occurred about 15 million years ago. It is a type of tektite.
Buy natural gemstones in our shop
Moldavite was introduced to the scientific public for the first time in 1786 as chrysolites from Tyn nad Vltavou in a lecture by Josef Mayer of Prague University, read at a meeting of the Bohemian Scientific Society, Mayer 1788. Zippe, in 1836, first used the term “Moldavite”, derived from the Moldau river in Bohemia, the Czech Republic, from where the first described pieces came.
The chemical formula is SiO2(+Al2O3). Its properties are similar to those of other types of glass, and reported Mohs hardness varies from 5.5 to 7. It can be transparent or translucent with a mossy green color, with swirls and bubbles accentuating its mossy appearance. The gemstone can be distinguished from green glass imitations by observing their worm-like inclusions of lechatelierite.
The total amount of stones scattered around the world is estimated at 275 tons.
There are three grades of this gemstone: high quality, often referred to as museum grade, medium quality and regular grade. All three grades can be told apart by their appearance. 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. High-quality stones are often used for hand-crafted jewellery.
There is a moldavite museum, Muzeum Vltavinu, in Cesky Krumlov, Czech Republic. The Moldavite Association was established in Ljubljana, Slovenia in 2014. The association researches, exhibits and promotes stones around the world and has member geologists from more than 30 countries worldwide.