View source for Ruby

{{otheruses}}
{{Infobox mineral
| name        = Ruby
| category    = [[Corundum]] variety, [[Oxide mineral]]
| boxwidth    = 
| boxbgcolor  = pink
| image       = Ruby gem.JPG
| imagesize   = 
| caption     = A ruby gemstone
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| formula     = [[aluminium oxide]] with [[chromium]], Al<sub>2</sub>O<sub>3</sub>
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| color       = Red shades
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| luster      = [[Lustre (mineralogy)|Vitreous]]
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| references  = <ref name=Mindat>{{cite web|url=http://www.mindat.org/min-3473.html |title=Ruby at Mindat |publisher=Mindat.org |accessdate=23 August 2013}}</ref>
}}

A '''ruby''' is  a kind of precious stone. It is often associated with [[emerald]], [[sapphire]] and [[topaz]].<ref name=Mindat/> It is usually red, but can sometimes be other colors.<ref name=Mindat/> It is formed of [[aluminum]] and [[oxygen]] (Al<sub>2</sub>O<sub>3</sub>),<ref name=Mindat/> and that means it's a kind of [[corundum]]. A small amount of [[chromium]] makes the color. They are the most popular red gemstone, and is aften linked with the birthmonth of July.

[[File:Ruby - Winza, Tanzania.jpg|thumb|Natural rubies]]

== Ruby Media ==
<gallery widths='160px' heights='100%' mode='traditional' caption=''>
File:Rubis gisements.jpg|The main ruby-producing countries

File:Corundum.png|Crystal structure of rubies

File: Ruby model.jpg|Crystal structure of ruby showing the substitution of Al{{sup|3+}} ions (blue) with Cr{{sup|3+}} (red). The substitution density of Cr{{sup|3+}} ions in this model is approximately 2%, approximating the maximum doping normally encountered.

File:Ruby transmittance.svg |Transmittance of ruby in optical and near-IR spectra. Note the two broad violet and yellow-green absorption bands and one narrow absorption band at the wavelength of 694 nm, which is the wavelength of the ruby laser.

File:Rubin (Corundum) - Hunza Valley, div. Gilgit, Northern Areas, Pakistan.jpg|Ruby (Corundum) - Hunza Valley, div. Gilgit, Northern Areas, Pakistan.

File:NMNH-Rubies-CroppedRotated.png|Rubies at the [[National Museum of Natural History]], [[Washington, D.C.]], USA

File:Ruby Eye Pendant.jpg|The Ruby Eye Amulet from Mesopotamia, Adilnor Collection, Sweden.
</gallery>
== References ==
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[[Category:Gemstones]]
[[Category:Birthstones]]
[[Category:Corundum]]