Decomposed granite

Targasonne granite decomposing into decomposed granite and grus ("granite pourri," rotten granite, and "arène granitique," granitic sand), at the "Chaos" (moraine of the same name, near Font-Romeu-Odeillo-Via in the southern French département (county) of Pyrénées-Orientales.[citation needed]

Decomposed granite is a kind of granite rock that is weathered to the point that the parent material readily fractures into smaller pieces of weaker rock. Further weathering yields material that easily crumbles into mixtures of gravel-sized particles known as grus that further may break down to produce a mixture of clay and silica sand or silt particles. Different specific granite types have differing propensities to weather, and so differing likelihoods of producing decomposed granite. It has practical uses that include its incorporation into roadway and driveway paving materials, residential gardening materials in arid environments, as well as various types of walkways and heavy-use paths in parks. Different colors of decomposed granite are available, deriving from the natural range of granite colors from different quarry sources, and admixture of other natural and synthetic materials can extend the range of decomposed granite properties.