Alexandrite


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alexandrite

[‚al·ig′zan‚drīt]
(mineralogy)
A gem variety of chrysoberyl; emerald green in natural light but red in transmitted or artificial light.

Alexandrite

 

the mineral variety of chrysoberyl, having a composition of BeAl2O6, with an admixture of Cr2O3 (up to 0.5 percent). Thick tabular crystals of a pseudohexagonal habit are characteristic. In sunlight, alexandrite is emerald green; under artificial light, violet-red. The hardness is 8.5 on the mineralogical scale, and the density is about 3,700 kilograms per cubic meter. Alexandrite with a rich color and a weight of more than 2–3 carats is a precious stone of the first class. The finest alexandrites from deposits in the USSR, Brazil, South Africa, Madagascar, and Ceylon are found in pegmatites. Synthetic alexandrite is the name given to the artificially produced, light-green variety of corundum.

alexandrite

type of chrysoberyl typifying undying devotion. [Gem Symbolism: Jobes, 67]
See: Loyalty
References in periodicals archive ?
Pulsed dye alexandrite laser (510 nm) successfully removes red tattoo pigment.
Treatment of Becker's nevi with a long-pulse alexandrite laser.
Laser-assisted hair removal: Side effects of Q-switched Nd:YAG, long-pulsed ruby, and alexandrite lasers.
In another study, a Q-Switched Alexandrite Laser (755 nm) provided a positive result, resolving the pigmented lesions but allowing mild repigmentation after two years [48].
Effective treatment of Futcher's lines with Q-switched alexandrite laser.
How the present owner came to possess the Alexandrite is unclear, more so as he prefers to remain anonymous but what is undisputed is that the gem has been named Alexandrite.
Dichromatism, the cause of the Usambara and the alexandrite colour-change effects.
Among them are, Ruby lasers, Dye lasers, Nd:Yag la- sers (Neomymium dimeium yatrium aluminum Garnet laser), Alexandrite, Excimer lasers, Co2 lasers.
The most common laser types used for hair removal are diode, ruby, Nd:Yag, and Alexandrite (12).
Alexandrite laser system (Light Age Epicare Duo) at 755 nm wavelength was used for the epilation procedure.
UC's Emma Alexandrite Duroy also contributed a gold in the 100-meter Butterfly event alongside Saint Theresa's College's Justie Reign Garrido, who topped the 100-m breaststroke event in the Boy's division and Tabunok Central School's Micah Marie dela Cerna, who ruled the 800-m freestyle competition.
Applications include, windows for ER:YAG, HO:YAG, and Alexandrite laser hand pieces, blood gas instruments, and sensors.