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

a ductile grey metallic element of the lanthanide series; used in lighter flints; the most abundant of the rare-earth group

a bivalent and trivalent metallic element of the rare earth group

a yellow trivalent metallic element of the rare earth group; occurs in monazite and bastnasite in association with cerium and lanthanum and praseodymium

a soft yellowish-white trivalent metallic element of the rare earth group; can be recovered from bastnasite or monazite by an ion-exchange process

a grey lustrous metallic element of the rare earth group; is used in special alloys; occurs in monazite and bastnasite

a ductile grey metallic element of the lanthanide series; used in lighter flints; the most abundant of the rare-earth group

a bivalent and trivalent metallic element of the rare earth group

a yellow trivalent metallic element of the rare earth group; occurs in monazite and bastnasite in association with cerium and lanthanum and praseodymium

a soft yellowish-white trivalent metallic element of the rare earth group; can be recovered from bastnasite or monazite by an ion-exchange process

a grey lustrous metallic element of the rare earth group; is used in special alloys; occurs in monazite and bastnasite