Vermiculite is a naturally occurring mineral that expands when heated. It is formed from the weathering of mica and has a unique, layered structure. When heated to high temperatures, vermiculite expands into lightweight, accordion-like particles, making it useful in various applications. This mineral is commonly used in gardening and construction. In gardening, it improves soil aeration and moisture retention, promoting healthy plant growth. In construction, vermiculite is used as insulation material due to its fire-resistant properties and ability to reduce sound transmission.