What does iridium mean?
Iridium is a rare, dense, silvery-white metallic element with an exceptionally high melting point and strong resistance to corrosion and chemical change. It belongs to the platinum group and occurs naturally in platinum-rich ores, often alongside osmium and other precious metals. Iridium's durability makes it valuable in industrial catalysts, high-temperature alloys, electrical contacts, and specialized equipment such as some fountain-pen nibs. It also has an important place in geology and paleontology: a worldwide layer rich in iridium in rock strata is known as the iridium anomaly and is associated with the asteroid impact implicated in the extinction of the non-avian dinosaurs. The name reflects the colorful compounds of iridium, whose salts helped inspire the element's identification. Although the metal itself is highly valued, its uses are specialized because it is expensive and comparatively rare. Its combination of hardness, heat resistance, and chemical stability makes it useful where ordinary materials would fail.
nounIridium is a hard, brittle, silvery-white metallic element of the platinum group, known for its high density, corrosion resistance, and exceptional resistance to extreme temperatures. It occurs in platinum ores and is used in industrial catalysts, high-temperature alloys, electrodes, and some fountain-pen nibs.
- The chemical element iridium, a dense, hard, silvery-white transition metal in the platinum group.
- An object or material made from, or containing, iridium.
"The spacecraft relied on iridium alloy components to withstand extreme temperatures during re-entry."
"Iridium is one of the rarest elements in Earth's crust."
"A thin layer of iridium was found in rocks associated with the ancient impact event."
A rare countable plural, used when referring to separate pieces or objects made of iridium.
"The laboratory keeps samples of iridiums in sealed containers."
Iridium's name comes from the Greek word for rainbow, a tribute to the vivid colors produced by some of its compounds.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does iridium come from?
The name iridium was coined in the early nineteenth century from Neo-Latin iridium, derived from Latin iris, meaning “rainbow,” in reference to the colors of iridium compounds. The Latin word is cognate with Greek iris, also meaning “rainbow,” and with English iris, the flower whose petals display a range of colors. The English adjective iridescent and the chemical term iridic share this root.
How iridium is actually used
In scientific and industrial contexts, iridium is normally treated as an uncountable mass noun. In general usage, it may refer to the metal itself or to a component made from it; plural forms are uncommon.