Formula: Al₂O₃
Mineral class: oxides
Crystal system: trigonal
Mohs scale: 9
Density (g/cm³): 3.9 - 4.1
Cleavage: -
Color: red in variations, caused by traces of iron, and up to 0.1% chromium oxide which partially replaces the aluminium oxide in the unit cell
Luster: vitreous
Fluorescence: strong carmine red
Pleochroism: yellowish-red - dark carmine red
Largest ruby: Rough: 8.184 kg measuring 130 mm x 138 mm x 145 mm (Source: http://www.guinnessworldrecords.com). Faceted: 23.1 ct
Faceted, best quality: 23.1 ct (Smithsonian Institution's National Gem and Mineral collection in Washington, D.C.)
Cabochon, best quality: 38.12 ct
Deposits: worldwide
Discovery: ?
1st Description: 1805

Ruby Mineral

Origin: Mogok Region / Mandalay / Myanmar

Photo by kind permission of © www.crystal-treasure.com, Sieghard Ellenberger.

Ruby Mineral

Origin: Mogok / Myanmar

Photo by kind permission of © www.crystal-treasure.com, Sieghard Ellenberger.

Ruby Mineral

Origin: Dattaw Mine / Mogok / Myanmar

Photo by kind permission of © www.crystal-treasure.com, Sieghard Ellenberger.

Ruby Mineral

Origin: Jagdalak Ruby Mine / Sorobi District / Konar Province / Afghanistan

Photo by kind permission of © www.irocks.com, Dr. Robert Lavinsky.

Ruby

Weight: 2.12 ct

Origin: Myanmar

Photo by kind permission of © www.multicolour.com, David Weinberg.

Ruby Mineral

Size: 1.43 x 1.41 x 1.1 cm

Origin: Mogok / Sagaing Distr. / Mandalay Div. / Myanmar

Photo by kind permission of © www.mineralman.com, Jasun McAvoy.

Ruby

Weight: 1.46 ct

Origin: Andilamena / Madagascar

Photo by kind permission of © www.multicolour.com, David Weinberg.

Ruby

Weight: 2.46 ct

Origin: Songea / Tanzania

Photo by kind permission of © www.multicolour.com, David Weinberg.

Ruby

Weight: 2.22 ct

Origin: Madagascar

Photo by kind permission of © www.multicolour.com, David Weinberg.

Ruby

Weight: 4.21 ct

Origin: Myanmar

Photo by kind permission of © www.edelsteine.at, Thomas Pfneisl.

Ruby

Weight: 1.03 ct

Origin: Namya / Myanmar

Photo by kind permission of © www.wildfishgems.com, Edward Bristol.

Ruby

Weight: 7.13 ct

Origin: Songea / Tanzania

Photo by kind permission of © www.multicolour.com, David Weinberg.

Ruby

Weight: 2.35 ct

Origin: Songea / Tanzania

Photo by kind permission of © www.multicolour.com, David Weinberg.

Ruby in Fuchsite

Size: 2.9 x 1.9 cm

Origin: Mysore / India

Photo by kind permission of © www.kristallplanet.de, Holger Andres.

Ruby in Marble

Size: 1.78 x 1.34 x 1.27 cm

Origin: Mong Hsu / Shan / Myanmar

Photo by kind permission of © www.crystal-treasure.com, Sieghard Ellenberger.

Ruby in Marble

Size: 3.52 x 1.63 x 0.2 ct

Origin: Russia

Photo by kind permission of © www.djraregems.com, Donna & John Rhoads.

Ruby in Zoisite

Size: 4.5 x 4 cm

Origin: Mundarara / Longido / Tanzania

Photo by kind permission of © www.kristallplanet.de, Holger Andres.

Ruby in Zoisite
Size: 4.8 x 2.0 x 0.45 cm
Weight: 63.96 ct
Origin: Tanzania

Photo by kind permission of www.online-edelstein.de, Timo Klopp.

Ruby-Zoisite Carving
Size: 6.3 cm high, 9.7 cm long Weight: 512 g
The carving is handmade from one piece of ruby-zoisite rock!
Artist: Gerd Dreher
Photo by kind permission of © www.dreher-carvings.com, Gerd Dreher.

Star Ruby "Star of Katandru"

Weight: 16.21 ct

Origin: Sri Lanka

Photo by kind permission of © www.mnh.si.edu/, Smithsonian National Museum of Natural History.
Photo: Chip Clark

Star Ruby

Weight: 6.40 ct

Origin: Sri Lanka

Photo by kind permission of © www.djraregems.com, John Rhoads.

Star Ruby

Photo by kind permission of © skywalker.cochise.edu, Roger Weller.

Ruby Trapiche

Photo by kind permission of © www.mineralman.com, Jasun McAvoy.

Ruby Trapiche

Origin: Mong Hsu / Myanmar

Photo by kind permission of © www.crystal-treasure.com, Sieghard Ellenberger.