Crossword clues for iridium
iridium
- Hard metal
- Two posh male guards deliver something metallic
- Metal named for the Greek goddess of the rainbow
- Most corrosion-resistant metal
- Metallic element used in spark plugs
- Heavy corrosion-resistant metal, used in alloys
- Heavy brittle metal used in alloys, Ir
- Extremely rare metal with atomic number 77
- Element often found in meteorites
- Element no. 77
- Element named for the rainbow
- Atomic number 77
- Platinumlike metal
- Metal in surgical tools
- Corrosion-resistant metal, Ir
- Platinum-group element
- Metal between osmium and platinum on the periodic table
- A heavy brittle metallic element of the platinum group
- Occurs in natural alloys with platinum or osmium
- Used in alloys
- Metal in the points of gold pens
- Metal used for points of gold pens
- Substance used by watchmakers
- Irish speaker’s turn of phrase in heavy metal
Longman Dictionary of Contemporary English
The Collaborative International Dictionary
iridium \i*rid"i*um\ ([-i]*r[i^]d"[i^]*[u^]m), n. [NL., fr. L. iris, iridis, the rainbow. So called from the iridescence of some of its solutions. See Iris.] (Chem.) 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 (2410[deg] C, versus platinum 1772[deg] C). With the exception of osmium, it is the heaviest substance known, its specific gravity being 22.4. Symbol Ir. Atomic weight 192.22.
Note: 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.
Douglas Harper's Etymology Dictionary
1804, Modern Latin, coined by its discoverer, English chemist Smithson Tennant (1761-1815) from Greek iris (genitive iridos) "rainbow;" so called for "the striking variety of colours which it gives while dissolving in marine acid" [Tennant]
Wiktionary
n. A metallic chemical element (''symbol'' Ir) with an atomic number of 77.
WordNet
n. a heavy brittle metallic element of the platinum group; used in alloys; occurs in natural alloys with platinum or osmium [syn: Ir, atomic number 77]
Wikipedia
Iridium is a chemical element with symbol Ir and atomic number 77. A very hard, brittle, silvery-white transition metal of the platinum group, iridium is generally credited with being the second densest element (after osmium) based on measured density, although calculations involving the space lattices of the elements show that iridium is denser. It is also the most corrosion-resistant metal, even at temperatures as high as 2000 °C. Although only certain molten salts and halogens are corrosive to solid iridium, finely divided iridium dust is much more reactive and can be flammable.
Iridium was discovered in 1803 among insoluble impurities in natural platinum. Smithson Tennant, the primary discoverer, named iridium for the Greek goddess Iris, personification of the rainbow, because of the striking and diverse colors of its salts. Iridium is one of the rarest elements in Earth's crust, with annual production and consumption of only three tonnes. Ir and Ir are the only two naturally occurring isotopes of iridium, as well as the only stable isotopes; the latter is the more abundant of the two.
The most important iridium compounds in use are the salts and acids it forms with chlorine, though iridium also forms a number of organometallic compounds used in industrial catalysis, and in research. Iridium metal is employed when high corrosion resistance at high temperatures is needed, as in high-performance spark plugs, crucibles for recrystallization of semiconductors at high temperatures, and electrodes for the production of chlorine in the chloralkali process. Iridium radioisotopes are used in some radioisotope thermoelectric generators.
Iridium is found in meteorites with an abundance much higher than its average abundance in Earth's crust. For this reason, the unusually high abundance of iridium in the clay layer at the Cretaceous–Paleogene boundary gave rise to the Alvarez hypothesis that the impact of a massive extraterrestrial object caused the extinction of dinosaurs and many other species 66 million years ago. Similarly, an iridium anomaly in core samples from the Pacific Ocean suggested the Eltanin impact of about 2.5 million years ago.
It is thought that the total amount of iridium in the planet Earth is much higher than that observed in crustal rocks, but as with other platinum-group metals, the high density and tendency of iridium to bond with iron caused most iridium to descend below the crust when the planet was young and still molten.
Iridium is a chemical element.
Iridium may also refer to:
-
Iridium satellite constellation, a constellation of satellites used to provide voice and data coverage
- Iridium Communications, the company that operates the satellite constellation
- Iridium Jazz Club, New York City, US
- Iridium High, a fictional high school in the television series Every Witch Way
Usage examples of "iridium".
The amount of iridium and the fact that some of the shocked quartz has double lamellae, however, more strongly argue for an extraterrestrial source.
Horn pens, tortoise-shell pens, nibs of diamond or ruby imbedded in tortoise shell, nibs of ruby set in fine gold, nibs of rhodium and of iridium imbedded in gold,-- all have been adopted at different times, but most of them have been found too costly for general adoption.
And, indeed, deep in the crust of the illuminated globe appeared a vague network of vanadiums, chromiums, and platinums, the platinum group including osmium and iridium.
The screener canisters were loaded with millimeter-sized iridium balls, unlike the fine powder the dusters carried.
This is pressure stamped under vacuum to produce ingots, which are electroplated with iridium to prevent corrosion and then warehoused.
Ferrol found quiet satisfaction in the feet that the dust, while loaded with strange and exotic silicates, contained not a single scrap of gold, platmium, or iridium.
And, indeed, deep in the crust of the illuminated globe appeared a vague network of vanadiums, chromiums, and platinums, the platinum group including osmium and iridium.
He insisted that the iridium had been deposited by volcanic action even while conceding in a newspaper interview that he had no actual evidence of it.
Like a monstrous cannonball, the titanic mass of iridium, more than a mile in diameter, ascends straight up through a billion tons of debris, the decimated seafloor crumbling within the vacuum of the rising colossus's wake.
Sometimes it was as if he were walking on the remains of organic machines—hybrid beings, half-animal, arisen from the union of the living and the nonliving, of reason and unreason—and sometimes it was as if he were bringing his iridium boots down on weirdly spreading gems, precious and impure, partially clouded due to interpenetrations and metamorphoses.
About revolts and secessions in the colony worlds, or the price of iridium, or inflation of the crown-"