Rare Double Opal Pineapple
Moldavite [ SiO2(+Al2O3) ]
Moldavite is a forest green, olive green or blue greenish vitreous silica projectile of rock formed by a meteorite impact in southern Germany (Nördlinger Ries Crater) that occurred about 15 million years ago. Moldavite is a type of tektite.
Because of their difficult fusibility, extremely low water content, and chemical composition, the current consensus among earth scientists is that moldavites were formed about 14.7 million years ago during the impact of a giant meteorite in the present-day Nördlinger Ries crater. Splatters of material that was melted by the impact cooled while they were actually airborne and most fell in Bohemia.
[ Excerpt from Wikipedia ]