What is obsidian?
Obsidian is naturally occurring volcanic glass. It is formed when lava cools rapidly.
It is either jet black or a glistening gray, depending on which direction it is cut.
Obsidian was discovered in Ethiopia by the Roman explorer Obsidius.
It has been found to have been used by Neolithic man 700,000 years ago.
It can be used to make extremely sharp knives much sharper than is possible with steel, with a cutting edge of just 3 nanometers wide.
Not surprisingly, it has been used to make many types of weapons and tools in the past. Today it is used mainly in jewelry and ornaments.