Pebblestone is a small, round, or irregular shaped rock used for decoration purposes. These stones are often found in natural settings such as river beds and beaches. Synonyms for pebblestone include cobbles, rocks, boulders, gravels, and stones. Cobbles are larger than pebblestones, while boulders are much bigger. Gravels are small fragments of rock, but they can also be used as decoration. Meanwhile, stones are a catch-all term for rocks of various sizes. Each of these synonyms can be used interchangeably with pebblestones depending on the context in which they are used. Whether you prefer large cobbles or small pebblestones, there is a natural stone for every landscaping need.