Rockall part of the deeply eroded Rockall Igneous Centre that was formed as part of the North Atlantic Igneous Province, approximately 55 million years ago, when the ancient continent of Laurasia was split apart by plate tectonics. Greenland and Europe separated and the northeast Atlantic Ocean was formed between them, eventually leaving Rockall as an isolated islet. The RV "Celtic Explorer" surveyed the Rockall Bank in 2003. The Irish Light Vessel "Granuaile" (the same name as the steamer on the RIA 1896 botany survey) was chartered by the Geological Survey of Ireland, on behalf of the Department of Communications, Marine and
Rockall climate without heat or cold extremes. Rockall 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. In 1975, a mineral new to science was discovered in a rock sample from Rockall. The mineral is called bazirite, named after the chemical elements barium and zirconium. Bazirite has the chemical composition BaZrSiO. Rockall forms