Ruby

Big Photo

Madagascar
6.29 carats
© gemselect.com

Ruby is a pink to blood-red coloured gem variety of the mineral Corundum. The name comes from the Latin word "ruber" - red.

The red colour can vary within each individual deposit, therefore the determination of the source from the colour is not possible. The red colour is caused by chromium, and in case of brownish tones due to presence of iron.

The rough stone has dull and greasy lustre.

Inclusions are common and often indicate that the stone is natural.

Ruby Gemstones by Colour

This table shows the variety of hues this gemstone can be found in. Click on a photo for more information.
 
 
 
 

Ruby Gemstones by Size

This table shows distribution of Ruby gemstone sizes that are listed on this site. This can give a good indication as to the general availability of this gemstone in different sizes.
Contributed photos
Lightest:0.12 cts
Heaviest:100.32 cts
Average:5.48 cts
Total photos:105
Do you have a larger Ruby? Why not upload a photo?
Significant stones
Eminent Star6,465 cts
Ecce Homo Star Ruby2,890 cts
Edwardes Ruby167 cts
Rosser Reeves Star Ruby139 cts
Anne of Brittany's105 cts
0.12ct to 10.14ct10.14ct to 20.16ct20.16ct to 30.18ct30.18ct to 40.20ct40.20ct to 50.22ct50.22ct to 60.24ct60.24ct to 70.26ct70.26ct to 80.28ct80.28ct to 90.30ct90.30ct to 100.32ct
General Information
A variety or type of:Corundum
Varieties/Types:
Flux-Grown Ruby - A synthetic ruby grown from alumina dissolved in a molten flux.
Geneva Ruby - Earliest synthetic rubies (circa 1885) created in Geneva.
Star Ruby - A chatoyant ruby showing asterism.
Verneuil Ruby - A synthetic ruby created using the flame fusion process.
Chemical Formula
Al
 
2
O
 
3
Michael O’Donoghue, Gems, Sixth Edition (2006)
Significant stones
ImageNameWeightCountry of OriginCurrent Owner
Eminent Star6,465.00 ctsIndia
Ecce Homo Star Ruby2,890.00 ctsMozambique
Edwardes Ruby167.00 cts
Rosser Reeves Star Ruby138.70 ctsSri Lanka
Anne of Brittany's105.00 cts
DeLong Star Ruby100.32 ctsMyanmarAmerican Museum of Natural History
De Long Star Ruby100.32 ctsMyanmar
Edith Haggin de Long Star Ruby100.32 ctsMyanmar
Click here to view all significant Ruby gemstones
Photos of natural/un-cut material from mindat.org
Ruby Treatments
Heat-treatment may create a superficial chalky-blue reaction. May be dyed (especially cabochons): color concentration in cracks. Acetone test.
Diffusion: may show orangy color concentration/rim under surface. May show blue haloes/spots (internal diffusion). May be surface diffused (chromium): rare. Glass filling: rounded and flattened gas bubbles, glassy residues. Reflecting light: filled cracks may show a distint surface luster. Lead-glass (and some other high refractive glasses) may be revealed by bluish to orangy flashes seen when looking parallel to filled cracks, using dark-field or fiber-optic light. Some glass-filled rubies may not show colored flashes nor show obvious gas bubbles. Sensitive to solvents - Blue Chart Gem Identification, Herve Nicolas Lazzarelli, 2010, p. 2
Ruby Simulants
Imitation rubies are also marketed. Red spinels, red garnets, and colored glass have been falsely claimed to be rubies. Imitations go back to Roman times and already in the 17th century techniques were developed to color foil red—by burning scarlet wool in the bottom part of the furnace—which was then placed under the imitation stone.
Synthetic Ruby
In 1837 Gaudin made the first synthetic rubies by fusing potash alum at a high temperature with a little chromium as a pigment. In 1847 Ebelmen made white sapphire by fusing alumina in boric acid. In 1877 Frenic and Freil made crystal corundum from which small stones could be cut. Frimy and Auguste Verneuil manufactured artificial ruby by fusing BaF2 and Al2O3 with a little Chromium at red heat. In 1903 Verneuil announced he could produce synthetic rubies on a commercial scale using this flame fusion process. By 1910, Verneuil's laboratory had expanded into a 30 furnace production facility, with annual gemstone production having reached 1,000 kg (2,205 lb) in 1907.

Other processes in which synthetic rubies can be produced are through the Czochralski's Pulling process, flux process, and the hydrothermal process. Most synthetic rubies originate from flame fusion, due to the low costs involved. Synthetic rubies may have no imperfections visible to the naked eye but magnification may reveal curves, striae and gas bubbles. The fewer the number and the less obvious the imperfections, the more valuable the ruby is; unless there are no imperfections (i.e., a "perfect" ruby), in which case it will be suspected of being artificial. Dopants are added to some manufactured rubies so they can be identified as synthetic, but most need gemological testing to determine their origin.
Synthetic rubies are used for watches and bearings, formerly the most important technical application for natural stones. - Gemstones of the world, Walter Schumann, 2001, p 82
Physical Properties of Ruby
Mohs Hardness9
Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010)
More from other references
Specific Gravity3.97 to 4.05
Walter Schumann, Gemstones of the world (2001)
More from other references
TenacityBrittle
Michael O’Donoghue, Gems, Sixth Edition (2006)
Cleavage QualityNone
Michael O’Donoghue, Gems, Sixth Edition (2006)
FractureConchoidal,Splintery
Walter Schumann, Gemstones of the world (2001) Small conchoidalMore from other references
Optical Properties of Ruby
Refractive Index1.762 to 1.778
Walter Schumann, Gemstones of the world (2001)
More from other references
Optical CharacterUniaxial/-
Michael O’Donoghue, Gems, Sixth Edition (2006)
Birefringence0.008
Michael O’Donoghue, Gems, Sixth Edition (2006)
PleochroismStrong: purplish-red - orangy-red
Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010)
More from other references
Dispersion0.018
Michael O’Donoghue, Gems, Sixth Edition (2006)
ChatoyancyStar 6
Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010)
Colour
Colour (General)Near colourless through pink through all shades of red to a deep crimson.
Michael O’Donoghue, Gems, Sixth Edition (2006)
Colour (Chelsea Filter)Fluorescent red
Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010)
Causes of ColourRed, Cr3+ in octahedral coordination with minor contributions of V3+ and Fe3+ in octahedral coordination.
W. William Hanneman, Pragmatic Spectroscopy For Gemologists (2011)
TransparencyTransparent,Translucent,Opaque
Walter Schumann, Gemstones of the world (2001)
LustreSubadamantine,Vitreous,Pearly
Michael O’Donoghue, Gems, Sixth Edition (2006) Pearly on parting surfaces
Fluorescence & other light emissions
Fluorescence (Short Wave UV)Inert to (strong) red
Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010)
Fluorescence (Long-Wave UV)Moderate to strong red. A red-inhibiting filter may reveal an orange fluorescence.
Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010)
Crystallography of Ruby
Crystal SystemTrigonal
Michael O’Donoghue, Gems, Sixth Edition (2006)
HabitHexagonal prisms or tables, rhombohedrons
Walter Schumann, Gemstones of the world (2001)
More from other references
Geological Environment
Where found:The host rocks of ruby are metamorphic dolomite marbles, gneiss and amphibolite. The yield of rubies from such primary deposits is not economically profitable. Rather secondary alluvial deposits are worked. Because of its high density, ruby is normally separated through the washing of river gravels, sands, and soil, then concentrated, and finally picked out by hand.
Walter Schumann, Gemstones of the world (2001)
Spectrographic Data
Calculated Spectra:
Click spectra for more information
Ruby - Locality: Hunza, Pakistan
Ruby - Locality: Winza, Tanzania
Ruby - Locality: Winza, Tanzania
Verneuil Ruby - Locality: Synthetic
Verneuil Ruby - Locality: Synthetic
Inclusions in Ruby
“Silk” intersecting at 60°-120° on the same plane and other guest crystals.
Heat-treated ruby: flux remnants in partially healed surface reaching cracks sometimes very similar to fingerprint pattern seen in synthetic flux; dot-like partially dissolved rutile needles (silk), rounded melted crystals - Blue Chart Gem Identification, Herve Nicolas Lazzarelli, 2010, p. 2
Inclusions are common. They are not always indicative of lower quality, but show the difference between a natural and synthetic stone. The type of inclusion (minerals, growth structures, canals or other cavities) often indicates the source area. Included rutile needles bring about either soft sheen (silk) or, when cut in cabochon, the rare cat's eye effect, or more often the very desirable asterism - a 6-rayed star, which shimmers over the surface of the stone when it is moved. - Gemstones of the world, Walter Schumann, 2001, p 82
Rutile inclusions
Inclusions:Rutile
Inclusions such as these rutile needles in ruby are often strikingly beautiful. Gemoloigsts study inclusions for clues about the origin and nature of gems.

Field of view 3mm
External Articles
LinkSourceDate
A Brief History of Heat - by Richard Hughesruby-sapphire.com1st Feb 2011
AIGS Master Colour Ruby Chartgemwow.com1st Jan 2010
Curse of the Gem of Tanzaniadailymail.co.uk5th Apr 2009
The Gem Spectrum: Burma Ruby [Vol. 1, No. 2, June 1995]palagems.com1st Jun 1995
Further Information
Mineral information:Ruby information at mindat.org
Significant Gem Localities
Afghanistan
 
  • Kabol Province (Kabul Province)
    • Surobi District (Sorobi District)
Gemexplorer.org; Garnier, V., Giuliani, G., Ohnenstetter, D., Fallick, A.E., Dubessy, J., Banks, D., Vinh, H.Q., Lhomme, T., Maluski, H., Pêcher, A., Bakhsh, K.A., Long, P.V., Trinh, P.T., and Schwarz, D. (2008): Ore Geology Reviews 34, 169-191.
Bowersox et al. (2000)
Bowersox et al. (2000)
Australia
 
  • New South Wales
    • Gloucester Co.
      • Barrington Tops
McClure and Smith (2001)
    • Selwyn Co.
      • Tumbarumba
McClure and Smith (2001)
Cambodia
 
  • Krong Pailin Municipality (Pailin Municipality)
Hughes (1997)
mindat.org
Hughes (1997)
Hughes (1997)
China
 
  • Yunnan Province
    • Yuxi Prefecture
      • Yuanjiang Co.
Galibert and Hughes (1995)
Colombia
 
  • Cauca Department
    • Mun. de Mercaderes
Johnson et al. (2000)
Greenland
 
  • Sermersooq
    • Nuuk (Godthåb)
Gemexplorer.org
India
 
  • Karnataka
    • Dakshina Kannada District (South Kanara; South Canara)
Mihelou (2006)
Mihelou (2006)
Kenya
 
  • Coast Province
    • Taita Taveta District
Mercier A., Debat P. & Saul J.M. (1999): Exotic origin of the ruby deposits of the Mangari area in SE Kenya. Ore Geology Reviews, 14, 83-104.
      • Tsavo West
Barot et al. (1995)
        • Tsavo West
Pardieu and Senoble (2005)
Madagascar
 
  • Antananarivo Province
    • Vakinankaratra Region
      • Antsirabé 2 District
Rakotosamizanany et al. (2009)
  • Toamasina Province (Tamatave)
    • Alaotra-Mangoro Region
      • Ambatondrazaka District
Hanni (2001)
    • Analanjirofo Region
      • Fenoarivo East District (Fenerive)
Leuenberger (2001)
Pardieu and Senoble (2005)
    • Eastern Region (Atsinanana Region)
      • Vatomandry District
Pardieu and Senoble (2005)
  • Tuléar Province (Toliara)
    • Anosy Region (Fort Dauphin Region)
      • Betroka District
        • Isoanala Commune
Rakotosamizanany et al. (2009)
    • Southwestern Region
      • Ampanihy District
        • Ejeda Commune
Rakotosamizanany et al. (2009)
        • Gogogogo Commune
Rakotosamizanany et al. (2009)
        • Vohitany Commune
Rakotosamizanany et al. (2009)
Malawi
 
  • Ntcheu District
Emmett (2000)
Mozambique
 
  • Cabo Delgado Province
Gemexplorer.org
Gemexplorer.org
  • Tete Province
    • Chimessolo
Pardieu et al. (2009)
Myanmar
 
  • Kachin State
    • Mohnyin District (Moe Hnyin District)
      • Hpakant Township (Hpakan; Phakant; Phakan)
Smith and Bosshart (2001)
  • Mandalay Division
    • Pyin-Oo-Lwin District
      • Mogok Township
        • Bernardmyo
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
        • Chaung-gyi
Ted Themelis (2008) Gems & mines of Mogok
[var: Star Ruby] Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
        • Kathé (Kathe)
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
        • Kin (Guard Post)
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
        • Kyatpyin Central
          • Baw-lon-gyi (Big Ball)
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
        • Kyatpyin North
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
        • Kyauk-Pyat-That
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Kane and Kammerling (1992)
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
          • Yadanar-kaday-kadar
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
        • Marble Ark
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
          • Pyaung-pyin
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
        • Mogok Valley
          • Dattaw Hill
            • Dattaw-mid
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
          • Ohngaing (Ohn Gaing; Ohn Kai)
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
        • Pein-Pyit (Painpyit; Pyan Pyit)
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
      • Thabeikkyin Township
Garnier et al. (2006)
    • Yamethin District
Ted Themelis (2008) Gems & mines of Mogok
  • Sagaing Division
    • Katha District
      • Wuntho Township
Ted Themelis (2008) Gems & mines of Mogok
  • Shan State
    • Loilem District (Loilen District)
Yui et al. (2008)
Nepal
 
  • Bagmati Zone
    • Dhading District
Smith et al. (1997)
Smith et al. (1997)
    • Rasuwa District
      • Somdang
Smith et al. (1997)
Pakistan
 
  • Gilgit-Baltistan (Northern Areas)
    • Gilgit District
Gemexplorer.org
Russia
 
  • Northern Region
    • Karelia Republic
      • Northern Karelia
  • Urals Region
    • Middle Urals
      • Sverdlovskaya Oblast'
        • Rezh District
E.Ya. Kievlenko (2003) Geology of gems, p. 62
        • Shilovka River
    • Southern Urals
      • Chelyabinsk Oblast'
        • Plast
          • Kochkar' District
  • Western-Siberian Region
    • Polar Urals
      • Tyumenskaya Oblast'
Grygoriev et al. (2000)
Sri Lanka
 
  • Central Province
E.G. Zoysa (1999)
  • North Central Province
    • Polonnaruwa District
E.G. Zoysa (1999)
  • Sabaragamuwa Province
    • Ratnapura District
E.G. Zoysa (1999)
Milisenda and Henn (1999)
E.G. Zoysa (1999)
E.G. Zoysa (1999)
Econ Geol (1981) 76:733-738
Switzerland
 
  • Ticino (Tessin)
    • Leventina
      • Piumogna Valley
Gemexplorer.org
Tajikistan
 
  • Viloyati Mukhtori Gorno-Badakhshan (Viloyati Badakhshoni Kuni)
Smith (1998)
E.Ya. Kievlenko (2003) Geology of gems, p. 50
Gemexplorer.org
Tanzania
 
  • Arusha Region
    • Lake Manyara
Dirlam et al. (1992)
    • Longido
      • Muriatata hills
Pardieu and Senoble (2005)
Pardieu and Senoble (2005)
  • Dodoma Region
    • Mpapwa District (Mpwampwa)
      • Mpapwa
Hanni (2008)
  • Morogoro Region
    • Kilosa District
Keller (1992)
    • Mahenge
Pardieu and Senoble (2005)
Pardieu and Senoble (2005)
Dirlam et al. (1992)
  • Ruvuma Region
    • Songea Urban District
Pardieu and Senoble (2005)
    • Tunduru District
gemexplorer.org
  • Tanga Region
Dirlam et al. (1992)
Thailand
 
E.Ya. Kievlenko (2003) Geology of gems, p. 44
    • Bo Rai District
E.Ya. Kievlenko (2003) Geology of gems, p. 66
USA
 
  • Georgia
    • Rabun Co.
      • Pine Mountain
  • Montana
    • Granite Co.
      • Rock Creek District
Emmett and Douthit (1993)
Allen (1991)
  • North Carolina
    • Clay Co.
    • Macon Co.
      • Cowee Valley
        • Ellijay District
          • Franklin
Vietnam
 
  • Nghe An Province (Nghe Tinh Province)
Kammerling et al. (1994)
  • Yenbai Province (Yen Bai Province)
Kammerling et al. (1994)
Kammerling et al. (1994)
Zimbabwe
 
  • Midlands
    • Gweru District (Gwelo District)
      • Somabula
L.F. Marsh and F. Mugumbate (2009)
Copyright © Jolyon & Katya Ralph 1993-2016. Site Map. Locality, gem & photograph data are the copyright of the individuals who submitted them. For more information please contact the . Gemdat.org is an online information resource dedicated to providing free gemmological information to all.