- a rare metal, formerly considered an element but later found to be a mixture of rare-earth elements neodymium and praseodymium: symbol, Di: the name is still used for naming oxides and salts
- any commercial mixture of rare-earth elements found in monazite sand
Origin of didymiumModL: so named (1841) by C. G. Mosander (see erbium) from Classical Greek didymos, twin (because associated, association with lanthanum) + -ium
- A metallic mixture, once considered an element, composed of neodymium and praseodymium.
- A mixture of rare-earth elements and their oxides used chiefly in manufacturing and in coloring various forms of glass.
Origin of didymiumFrom Greek didumos twin, double ( from the fact that it was usually found associated with the previously discovered lanthanum ); see dwo- in Indo-European roots.