atomic number 4, Be, beryllium, glucinium - a light strong brittle gray toxic bivalent metallic element

atomic number 58, Ce, cerium - a ductile gray metallic element of the lanthanide series; used in lighter flints; the most abundant of the rare-earth group

atomic number 68, Er, erbium - a trivalent metallic element of the rare earth group; occurs with yttrium

atomic number 64, gadolinium, Gd - a ductile silvery-white ductile ferromagnetic trivalent metallic element of the rare earth group

atomic number 67, Ho, holmium - a trivalent metallic element of the rare earth group; occurs together with yttrium; forms highly magnetic compounds

atomic number 65, Tb, terbium - a metallic element of the rare earth group; used in lasers; occurs in apatite and monazite and xenotime and ytterbite

atomic number 70, Yb, ytterbium - a soft silvery metallic element; a rare earth of the lanthanide series; it occurs in gadolinite and monazite and xenotime

atomic number 39, Y, yttrium - a silvery metallic element that is common in rare-earth minerals; used in magnesium and aluminum alloys

mineral - solid homogeneous inorganic substances occurring in nature having a definite chemical composition