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Overview
About Ruby
Rubies can command the highest per-carat price of any coloured stone. This makes ruby one of the most important gems in the coloured stone market. In its purest form, the mineral corundum is colourless. Trace elements that become part of the mineral’s crystal structure cause variations in its colour. Chromium is the trace element that causes ruby’s red colour.
Birthstones & Anniversaries
Ruby is the birthstone for July and the gem for the 15th (in the U.S.) and 40th anniversaries.Ratnaraj
In Sanskrit, ruby is ratnaraj, meaning the king of gems.
Mogok
Myanmar’s legendary valley of rubies; the source of many of the world’s most fabulous gems.
$32.4 million (£20.7 million)
On 12 May 2015, a 25.59 carat ruby ring sold for $1,266,901 (£810, 690) per carat, setting a new record at auction for a coloured gemstone.
Facts
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Mineral:
Corundum
Chemical composition
Treatments
There are a number of processes used to alter the colour or apparent clarity, or to improve the durability of gems.
Learn MoreSynthetics
Some gemstones have synthetic counterparts that have essentially the same chemical, physical and optical properties, but are grown by man in a laboratory.
Learn MoreImitations
Any gem can be imitated – sometimes by man-made materials or by natural materials chosen by man to impersonate a particular gem.
Learn More
Why We Love This Gemstone
Intense Red Glow
Fine ruby glows with intense red in sunlight thanks to red fluorescence, which intensifies its red colour.
First laser
The first laser was created in1960 using the red fluorescence light emitted by ruby.
Chromium
Chromium causes ruby's red. Gemologists consider it the "rock star" of trace elements.
Quality Factors
The prices of fine-quality rubies have been breaking auction records.
Colour
Colour is the most significant factor affecting a ruby’s value: Fine gems are a pure, vibrant red to slightly purplish red.
Clarity
If a ruby's inclusions affect its transparency or brilliance they reduce the gem’s value significantly.
Cut
Rubies are commonly fashioned as mixed cuts, which have brilliant-cut crowns and step-cut pavilions.
Carat Weight
Fine-quality rubies over one carat are very rare and price goes up significantly as size increases.
Ruby Quality Factors: The Comprehensive Guide
Research
Explore sources, gemmological research and the role of gems in history.
Ruby and Sapphire Production and Distribution: A Quarter Century of Change
Russell Shor and Robert Weldon Read more in EnglishIdentification and Durability of Lead Glass–Filled Rubies
Shane F. McClure, Christopher P. Smith, Wuyi Wang, and Matthew Hall Read more in English
