Rockall during a lightning storm. Rockall Island is one of the few pinnacles of the Helen's Reef, the surrounding elevated seabed is called the Rockall Bank. It is a tiny, inhospitable, uninhabited granite island that juts out of the North Atlantic about 300km from Scotland and 423km from Ireland. Is made of a type of peralkaline granite that is relatively rich in sodium and potassium. Within this granite are darker bands richer in iron because they contain two iron-sodium silicate minerals called aegirine and riebeckite. The darker bands are a type of granite that geologists have named "rockallite", although use of this term is now discouraged. Iceland has reasserted its claim over waters around Rockall. The UK has long had a claim over Rockall, although this is not recognised by a number of neighbouring states. The waters around the rock are rich in oil and gas opportunities, as well as fish. Fishing is expected to be banned near the Atlantic islet of Rockall after a rare methane gas vent in the seabed and two new shellfish species were discovered by British scientists.