Bilitonite

This tektite was formed millions of years ago by the collision of a meteorite with a layer of earth containing sand particles and trace metals on the island of Belitung in Indonesia. When the meteorite fell, it reacted with the high tin content (tin mines) on this island and formed the black rock that was later called Batu Satam. Due to this process, this tektite can only be found in Indonesia and is sought after by collectors worldwide.