6.90-6.966 Ytterbium was discovered by Marignac in 1878. Ytterbium has a bright silvery luster, is soft, malleable, and quite ductile. Ytterbium is fairly stable, but it is attacked by mineral acids and water. There are three known allotropic forms of ytterbium. The beta form ordinarily has metallic-type conductivity, but becomes a semiconductor when the pressure is increased above 16,000 atm.
Natural ytterbium is a mixture of seven stable isotopes, with seven other unstable isotopes known.
Few uses of ytterbium have been found, but possible uses for improving grain refinement, strength, and other mechanical properties of stainless steel are being explored.