• WordNet 3.6
    • n iridium a heavy brittle metallic element of the platinum group; used in alloys; occurs in natural alloys with platinum or osmium
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Webster's Revised Unabridged Dictionary
    • n iridium (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° C, versus platinum 1772° C). With the exception of osmium, it is the heaviest substance known, its specific gravity being 22.4. Symbol Ir. Atomic weight 192.22.☞ 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.
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Century Dictionary and Cyclopedia
    • n iridium Chemical symbol, Ir; atomic weight, 193. A metal of silver-white color, belonging to the platinum family, and, so far as known, always present in native platinum. Various analyses of Russian platinum give from a trace to 2½ per cent. of iridium; and analyses of Californian platinum give from 0.85 to 4.20 per cent. of the same. Iridium also occurs combined with osmium, forming what is known as iridosmium or iridosmine, which also contains more or less ruthenium and rhodium. (See iridosmium.) Little is known of the qualities of the metal iridium, except as it has been artificially prepared; and even in this way it has never yet been obtained perfectly free from other metals. Iridium as manufactured by Matthey, to be used in the alloy of platinum and iridium, at the recommendation of the International Commission of Weights and Measures, for the standard kilogram and meter, had (the purest obtained) a specific gravity of 22.38. The alloy thus prepared, which contained about 10 per cent. of iridium, is believed to possess those qualities desirable in a standard weight or measure, which is intended to be preserved for all time, in a higher degree than any other known substance or combination of substances. For the geographical distribution of the various members of this group of metals, see platinum.
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Chambers's Twentieth Century Dictionary
    • n Iridium ī-rid′i-um the most infusible, and one of the heaviest, of the metals, found associated with the ore of platinum, so called from the iridescence of some of its solutions
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Webster's Revised Unabridged Dictionary
NL., fr. L. iris, iridis, the rainbow. So called from the iridescence of some of its solutions. See Iris
Chambers's Twentieth Century Dictionary
Gr. iris, iridos, the rainbow.


In literature:

IRIDIUM, a metallic elementary body of rare occurrence, and found in the ores of platinum.
"The Nuttall Encyclopaedia" by Edited by Rev. James Wood
Iridium is mixed with platinum in order to increase its strength and durability.
"Scientific American Supplement, No. 520, December 19, 1885" by Various
The metals platinum, iridium, rhodium, osmium and palladium do not fuse.
"A System of Instruction in the Practical Use of the Blowpipe" by Anonymous
The points of our gold pens are tipped with an osmium-iridium alloy.
"Creative Chemistry" by Edwin E. Slosson
The syringe is made of glass, and has a solid glass piston; the needle of platino-iridium should be 5 cm.
"Manual of Surgery" by Alexis Thomson and Alexander Miles
The six-inch tungsto-iridium wall had been melted through.
"The Black Star Passes" by John W Campbell
I tried to get him to work on the iridium-osmium problem, but he refused.
"The Skylark of Space" by Edward Elmer Smith and Lee Hawkins Garby
Platinum 90 per cent, iridium 10 per cent.
"On Laboratory Arts" by Richard Threlfall
It could be iridium or platinum, of course.
"The Bramble Bush" by Gordon Randall Garrett
I guess it's the filth within these croupier types that makes them surround themselves with the aseptic immaculacy of iridium and glass.
"Vigorish" by Gordon Randall Garrett

In news:

Three jazz bands compose 'The Mingus Legacy' at Iridium .
JORI KLEIN/FOR THE STAR LEDGER Mingus Dynasty trumpet player Tatum Greenblatt, left, and bassist Dwayne Burno at the Iridium Jazz Club on Tuesday.
Iridium Jazz Club, 1650 Broadway at 51st Street, New York.
AirCell and Iridium Form Partnership.
AirCell and Iridium Satellite have reached an agreement that will allow AirCell to offer Iridium -based satellite communications products and services.
Iridium Available for UniLink Users.
Long after its satellites are permanently pulled from orbit, Iridium will be remembered for two things.
Gen Leonid Shershnev surprised us Tuesday with his strange charge that the United States had engineered the collision between America's Iridium 33 and Russia's Cosmos 2251 satellites over Siberia on Feb 10.
Here, Iridium satellite orbits and collision debris clouds.
PAINT YOUR WAGON The FX35 Limited Edition comes in only one color, Iridium Blue.
Iridium Adds ADS-B to its Iridium NEXT Constellation .
Beam Granted World's First Approval for Iridium Extreme Docking Station.
"Rebel Yell" by Steve Stevens and Sebastian Bach at Iridium.
Watch Live Broadcast of Steve Stevens and Sebastian Bach at Iridium Saturday Night.
Autolite Xtreme Sport Iridium Spark Plugs Side View.

In science:

The station communicates via an Iridium satellite modem. During the summer, it also had a wired Ethernet connection which was connected to a wireless Bridge station. This station communicated with a repeater which was installed on Mt.
A prototype station for ARIANNA: a detector for cosmic neutrinos
WiFi link and the Iridium modem and external signals like short wave radio stations.
A prototype station for ARIANNA: a detector for cosmic neutrinos
In addition to the USB interface the CPU uses several serial ports to talk to peripherals and a Analog/Digital I/O card. The serial ports are assigned to a serial console for debugging work, to an Iridium data modem, and to three GPS receivers.
A prototype station for ARIANNA: a detector for cosmic neutrinos
The switches control the RF amplifier, SCA and readout, GPS units, Iridium modem, Trimble GPS, anemometer, heartbeat pulser, and the Ethernet media converters.
A prototype station for ARIANNA: a detector for cosmic neutrinos
After the wireless link was removed, the station communicated via an Iridium satellite modem. It is configured to „call home‟ once every 15 minutes during the summer and 3h during the winter, giving housekeeping data and a few sample waveforms.
A prototype station for ARIANNA: a detector for cosmic neutrinos