Obsidian is a volcanic glass resulting from the near complete cooling of gas-less and therefore very viscous lava.
As soon as it leaves the crater, the lava cools rapidly, which does not allow the various atoms to crystallise properly, forming a glass-like structure. Obsidian is a natural glass, very similar to that of human production.
Much sought after in antiquity for the manufacture of sharp tools (mainly knives), it was one of the goods that animated trade in the Mediterranean and supported the economy of its places of extraction, such as Sardinia, the Aeolian Islands and Pantelleria, in prehistoric times.
Today it is still used in small decorative objects, jewellery and scalpel blades.
