They have names that sound borrowed from a fantasy novel: melilitite, nephelinite, ultramafic lamprophyre, kimberlite. Until quite recently they were mostly the preserve of mineralogy textbooks New! Sign up for our email newsletter on Substack. New! Sign up for our email newsletter on Substack. They have names that sound borrowed from a fantasy novel: melilitite, nephelinite, ultramafic lamprophyre, kimberlite. Until quite recently they were mostly the preserve of mineralogy textbooks