Perlite is a naturally occurring volcanic glass that is widely used in horticulture and construction industries. It has the unique property of expanding when heated, making it an ideal material for lightweight concrete and insulation. In addition to perlite, other synonyms for this material include expanded perlite, expanded volcanic rock, and perlite ore. The term perlite is often used interchangeably with similar materials such as vermiculite and pumice, which also share the property of expanding when heated. Other less commonly used synonyms for perlite include popcorn rock, bubble rock, and sponge rock. Regardless of the name, perlite continues to be a versatile and in-demand material for various applications.