Nama dan simbol kimia mereka ialah skandium (Sc), yttrium (Y), lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu) , gadolinium (Gd), terbium (Tb), disprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), lutetium (Lu). Nombor atomnya ialah 21 (Sc), 39 (Y), 57 (La) hingga 71 (Lu).