Volcanic glass is a natural glass formed when lava cools rapidly, preventing the formation of crystals. This process typically occurs during volcanic eruptions when molten rock is expelled and solidifies quickly upon contact with air or water. The most common type of volcanic glass is obsidian, which is known for its smooth texture and shiny appearance. Another type of volcanic glass is pumice, which is light and porous due to gas bubbles trapped during the cooling process. Both types of volcanic glass are used in various applications, including tools, decorative items, and even as an abrasive material in cleaning products.