galet or galet roulé is a French term for a pebble, cobble, or even a boulder (see geology) that is well rounded due to abrasion through continual rolling in fast-moving water.
The celebrated river-worn galets of châteauneuf-du-Pape and other parts of the southern rhône are composed of strikingly pure white quartzite
. Although it is probably the underlying clays and sands that are more significant for vine growth, these galets are so iconic that the name is now applied to rounded rock fragments in other vineyard regions, irrespective of their composition. In the Boutenac area of corbières, for example, the galets are formed from a brown-stained quartzite; in California’s arroyo seco, galets are a mixture of rock types; and Walla Walla, washington, has old river channels filled with galets of dark basalt.
