A steel‐gray hard ductile metallic element with a high melting point that occurs widely in combined forms. It is highly resistant to corrosion, and is used especially in alloys and in refractories and ceramics.
A metallic element found only in combination; atomic weight, 91.22; atomic number, 40. It is used in corrosion-resistant alloys and as a white pigment in dental porcelain and other ceramics.