Black Obsidian is a naturally occurring volcanic glass formed when lava rich in silica cools rapidly, preventing the formation of a crystalline structure. Its deep, glossy black appearance is the result of this fast cooling process, and it can sometimes display a slight sheen or iridescence depending on the presence of microscopic mineral inclusions. It has been used by humans for thousands of years — prized by ancient civilisations for making cutting tools, weapons, and ceremonial mirrors due to its ability to fracture into extremely sharp edges. Notable deposits are found in Mexico, the USA, and Iceland, where volcanic activity has historically been abundant.
