40.63 Carat Loose Ruby: 'Heart of the Kingdom' 
21.3 Carat Burmese Loose Ruby: 'The Carmen Lúcia Ruby'
About Loose Ruby
A loose ruby is a colored gemstone varying in color from pink to blood red and can have purple or even orange hues.
Loose rubies are naturally occurring and have also been synthesized since 1837.
Valuation of Loose Ruby
Similar to the 4c's used to grade diamonds, ruby is valued using the same criteria. Color, Cut, Clarity and Carat Weight!
Color: As practiced in the evaluation of colored gemstones color is the most imporant component and is divided into three parts, hue, saturation and tone. The finest rudy is vivid medium to dark toned red, with purple being the most prized secondary hue as it strengthens the primary red making it appear richer.
Record Breaking Loose Rubies!
The largest well known jewelry rubies are 40.63 carats and 32.1 carats.
Heart of the Kingdom
The first record holding heart shaped ruby known as the 'Heart of the Kingdom' was unveiled in 2007 by the London Jewler Garrand & Co. This ruby was found in Burma and is mounted on a $14 Million dollar, 155 carat diamond necklace and is simply exquisite! Burmese rubies very rarely exceed more than a 20 carats, so this loose ruby is truly a rare item indeed!
The Carmen Lúcia Ruby
Donated to the Smithsonian's Natural Museum of Natural History, The Carmen
Lúcia Ruby is a stunning 23.1 carat Burmese Ruby with a rich homogenous
deep red with amazing transparancy. Mined in the Mogok region of Burma in
the 1930's the ruby is set in platinum ring with diamonds.
This record breaking ruby was donated by businessman and philanthropist
Peter Buck in memory of his wife Carmen Lúcia.
General Loose Ruby Facts
Category: Mineral
Chemical formula: aluminium oxide with chromium, Al2O3:Cr
Identification: Color Red, may be brownish, purplish or pinkish
Crystal habit: Varies with locality. Terminated tabular hexagonal prisms.
Crystal system: Trigonal (Hexagonal Scalenohedral) Symbol (-3 2/m) Space
Group: R-3c
Fracture: Uneven or conchoidal
Mohs scale hardness: 9.0
Luster: Vitreous
Streak: white
Diaphaneity: transparent
Specific gravity: 4.0
Refractive index: nω=1.768 - 1.772 nε=1.760 - 1.763, Birefringence 0.008
Pleochroism: Orangey red, purplish red
Ultraviolet: fluorescence red under longwave
Melting point: 2044 °C
Solubility: none
Major varieties: Sapphire Any color except red, Corundum various colors, Emery Granular.