iridium

• POS: Noun
• HYPHEN: i=rid=i=um

CIDE DICTIONARY

iridium, n. [NL., fr. L. iris, iridis, the rainbow. So called from the iridescence of some of its solutions. See Iris.].

 A rare metallic element of atomic number 77, of the same group as platinum, which it much resembles, being silver-white and indifferent to most corrosive agents, but harder, more brittle, and with a higher melting temperature (24101913 Webster]
" Iridium usually occurs as a native alloy with osmium (iridosmine or osmiridium), which may occur alone or with platinum. Iridium, as an alloy with platinum, is used in bushing the vents of heavy ordnance. It is also used for the points of gold pens, and in a finely powdered condition (iridium black), for painting porcelain black."  [1913 Webster]

OXFORD DICTIONARY

iridium, n. Chem. a hard white metallic element of the transition series used esp. in alloys.

Usage

Symb.: Ir.

Etymology

mod.L f. L IRIS + -IUM