Cerpourt Polished Pebbles for Garden Plants | Natural Stone DecorCerpourt Polished Pebbles for Garden Plants Natural Stone Decor Natural Polished Gravel: It comes with 5lb Natural Polished GravelThese rocks are polished so they are natural and suitable for a variety of purposes. As stone rocks are natural substances, some may be broken or out of shape. Generally, the shapes of pebbles are oval or round, with uneven thickness Color & Size: River rocks are available in a wide range of sizes, ranging from 0. 8 to 1. 2