Hyaloclastite - a volcanic rock composed primarily of glasses and glassy tuff Icelandite - a volcanic rock Ignimbrite - a fragmental volcanic rock Ijolite - a very rare silica-undersaturated plutonic rock Kimberlite - a rare ultramafic, ultrapotassic volcanic rock and a source of diamonds Komatiite - an ancient ultramafic volcanic rock Lamproite - an ultrapotassic volcanic rock Lamprophyre - an ultramafic, ultrapotassic intrusive rock dominated by mafic phenocrysts in a feldspar groundmass
