Obsidian is a natural stone that formed from quickly cooled volcanic lava.
It is naturally dark in color due to the presence of magnesium and iron. As a type of volcanic glass, it has a glassy texture and a vitreous luster. The stone is also known for being brittle.
While obsidian is often thought to be a crystal, it is actually a glass-like igneous rock that solidified without crystallization. Thus, it’s not a true mineral but a mineraloid made of natural glass.
