metallic element, 1863, so called because it figures in the composition of the pale green precious stone beryl and was identified in emerald (green beryl) in 1797 by French chemist Louis Nicolas Vauquelin (1763-1829) and first isolated in 1828. At first and through 19c. also sometimes called glucinum or glucinium.
beryllium be·ryl·li·um (bə-rĭl'ē-əm)
A lightweight, corrosion-resistant metallic element used as an aerospace structural material, as a moderator and reflector in nuclear reactors, and in a copper alloy for springs and electrical contacts. Atomic number 4; atomic weight 9.0122; melting point 1,278°C; boiling point 2,471°C; specific gravity 1.848; valence 2.
A hard, lightweight, steel-gray metallic element of the alkaline-earth group, found in various minerals, especially beryl. It has a high melting point and is corrosion-resistant. Beryllium is used to make sturdy, lightweight alloys and aerospace structural materials. It is also used as a neutron moderator in nuclear reactors. Atomic number 4; atomic weight 9.0122; melting point 1,278°C; boiling point 2,970°C; specific gravity 1.848; valence 2. See Periodic Table.