In Britain they occur in Skye as lava flows and as dikes or intrusions, but they are much more common on the continent of Europe, as in the Rhine district and the Eifel, also in Auvergne, Bohemia and the Euganean Hills.
Di Inggris mereka terjadi di Skye sebagai aliran lava dan sebagai intrusi dike, tetapi mereka jauh lebih umum di benua Eropa, seperti di distrik Rhein dan Eifel, juga di Auvergne, Bohemia dan Euganean Hills.