Moldavite is a green tektite. A tektite is an impact glass, created due to the impact of a meteorite with the earth's crust. It is believed that the meteorite that created the Ries Kessel (a massive 15 mile diameter crater), 120 miles away in Germany "splashed," hot material into the atmosphere that cooled as it fell back to Earth. This impact material, landed across a relatively small (10 to 15 square mile) area in the current Czech Republic. This impact event is dated around 15 million years ago. Moldavite miners must dig holes to access this old layer in which the Moldavite is found. Moldavite is typically quite small, with the largest pieces generally available, weighing between 30 to 50 grams (up to 6-7 cm long). Moldavite is valued for its size (larger pieces are much rarer), condition (lack of damage), an attractive green color, and how textured, or "spikey," the surface is. 

This extra large piece of Moldavite weighs 31.4 grams. It has fantastic color, and is transparent inside. It has a natural crescent shape, which is one of the indicative tektitic shapes. It has an interesting textured surface as well. Overall this is a great piece worthy of any collection. Pieces over 30 grams are getting increasingly rare to find, and continue to go up in price.