Promethium Promethium Definition Promethium is a radioactive metallic element of the lanthanide series, which is does not occur in nature but is prepared through the fission…
Thulium Thulium Definition Thulium is a soft, silver-gray metallic element of the lanthanide series with symbol Tm. Its Atomic number 69; atomic weight 168.934; melting point…
Samarium Samarium Definition Samarium is a silvery-white metallic element of the lanthanide series that exists in several forms and has seven naturally occurring isotopes. Its atomic…
Lutetium Lutetium Definition Lutetium is a silvery-white metallic element of the lanthanide series that is used in nuclear technology. It is the last element in the…
Euxenite Euxenite Definition Euxenite is a rare brownish-black mineral containing erbium, cerium, uranium, columbium, and yttrium. Titanium replaces niobium–tantalum in the molecular structure to form the…
Ytterbium Ytterbium Definition Ytterbium is a soft, silvery-white metallic element of the lanthanide series that occurs as seven stable isotopes with symbol Yb. Its atomic number…
Praseodymium Praseodymium Definition Praseodymium is a soft, malleable, silvery metallic element of the lanthanide series that develops a green tarnish in air. It is the third…
Cerium Cerium Definition Cerium is a shiny, gray metallic element of the lanthanide series. It is ductile and malleable and is used in electronic components, alloys,…
Aragonite Aragonite Definition Aragonite is a usually white, yellowish, or pink orthorhombic mineral that can occur in many different colors. It is a polymorph of calcite,…
Crocoite Crocoite Definition Crocoite is a rare orange secondary mineral consisting of lead chromate in monoclinic crystalline form. It’s mineral consisting of lead chromate, PbCrO4, that…
Calcite Calcite Definition Calcite is a usually white, clear, pale-yellow or blue orthorhombic mineral. Calcite occurs in many different forms and is the main component of…
Holmium Holmium Definition Holmium is a soft, silvery, malleable metallic element of the lanthanide series. Its compounds are highly magnetic. Its atomic number 67; atomic weight…