Barstowite, formula Pb4[Cl6|CO3]•H2O, is a transparent to white mineral in the monoclinic system.

[2] It has a Mohs hardness of 3, a white streak and an adamantine lustre.

[2] The type locality for Barstowite is Bounds Cliff, St Endellion, Cornwall in the United Kingdom.

[2] It is named after Richard W. Barstow[2] (1947–1982), a Cornish mineral collector.

This article about a specific carbonate mineral is a stub.