Obsidian is a volcanic glass that forms when lava cools very quickly and consists of a solid mass of glass through and through. Why is obsidian not classified as a mineral?

Obsidian is classified by mineralogy as glass, since its atoms do not form a crystalline structure; It is hard and fragile, attractive, transparent and translucent, but its main feature is its type of fracture, sharp, straight and very sharp, which allows the development of various types of carved instruments and precious polished objects.

Explanation:

Obsidian is a volcanic glass that forms when incandescent lavas, at 600 ° C, with a high silica and aluminum content cool rapidly; If the temperature drop is slow, then the minerals crystallize and give rise to the rocks known as rhyolites, which are light colors: gray, brown, pink, reddish and yellowish.

The obsidian is usually black or gray, but it can also be reddish, brown, green or with different colored eyes; its transparency, translucency and brightness depend on the thickness of the fragment and the light under which it is observed. Obsidian is the most efficient natural material for the elaboration of cutting instruments, such as knives, and impact penetration, such as arrowheads. Due to its particular physical properties, obsidian was widely used by pre-Hispanic cultures in the elaboration of instruments such as sharp knives and uniform edges, for cutting plant fibers, feathers, wood and skins; maguey scrapers; leather, bone and wood perforators. It was also used to carve penetrating arrowheads, dart, spearheads and knives of various shapes. Aztec warriors, priests and gods carried various obsidian objects, such as necklaces, earmuffs, bezotes and scepters; also, urns and sculptures were made with that material.