The crescentic dune, also called the barchand dune, is the most common type of sand dune. As its name suggests, this dune is shaped like a crescent moon with points at each end, and it is usually wider than it is long. Crescentic dunes form when winds blow from one direction. This dune traverses desert surfaces faster than any other type of dune. The migrating dunes in China are crescentic dunes.

Jest to barchan, czyli wydma sierpowa charakterystyczna dla pustyni piaszczystych (ergów). Jej ramiona ułożone są zgodnie z kierunkiem wiatru.