Pica Glass is an impactite formed by the impact of a comet with the Earth in the north of Chile 12000 years ago. The tremendous amount of energy generated by the impact, made the sand of the desert melt, forming this glass when it solidified again. Inside this glass there are particles of the comet that mixed with the terrestrial material. This comet is known to have been similar to Comet Wild 2. This event took place in the same time a great extintion took place in South America so more than likely, the 2 events are related. Pica Glass is found near the town of Pica, hence its name. It forms part of a group of rock types and structures that are known as impactites. Certificate of authenticity included. IMCA 5591. Packages are usually sent the morning after the auction. Shipping is combined in all my listings - if you win multiple items, only one shipping cost is paid. Do not miss this opportunity!