Rubies are the second most valuable gemstone, and they mesmerize with their brilliant, blood-red color. Their color is directly due to the formation of the gem. The color of this stone is so desirable that its very name is taken from the Latin word “Ruber,” meaning “red.”
The trace element Chromium is responsible for giving Rubies their red coloring. The most expensive rubies will have a pure red color with high fluorescence. The higher the amount of Chromium present, the darker the hue of Red. The shade of Red differs in each Ruby from dark orange to purple-red, but the most valuable color is pigeon-blood Red.
While other precious stones like diamonds and emeralds can have various colors, this distinct red coloring defines a ruby. But which shade of Red is most desirable, and where can one mine the most valuable rubies?
Why Are Rubies Red And Sapphires Blue?
Sapphires and Rubies are essentially formed from the same chemical compound called Corundum. Corundum is a tough crystallized form of aluminum oxide. Essentially Corundum is transparent, but its color is affected by the number of trace elements in its structure.
Trace elements Iron and Titanium will produce a blue color in Sapphires. However, not all are blue. There is a large spectrum of colors, such as yellow, pink, black, white, green, or pink.
Chromium is what differentiates Rubies from Sapphires, as this is what is responsible for their red color. The higher the amount of the element Chromium, the deeper and more brilliant the red color is.
How Do Rubies Get Their Red Color?
Corundum, the compound rubies are formed from, contains varying amounts of iron, titanium, vanadium, and Chromium trace elements. There are also transition metals present in Corundum, which is responsible for their color.
Scientists have more than one definition for transition metal (or transition element). It is fundamentally a metal that has undergone a transition series of changes in the inner layer of electrons.
Corundum is a tough substance and, in its purest form, can have a reading of 9.0 on the Mohs scale. This means that it is not easily scratched or cracked. Corundum is also naturally transparent and receives its color from other trace elements present in its structure.
Cheaper rubies or fake gems parading as rubies can easily be scratched, and the color could even fade or peel off. So do proper due diligence when buying jewels.
For Corundum to be classified as a ruby, the trace element Chromium must be present. Higher levels of Chromium will result in darker, more saturated shades of Red.
How Is The Red Color In Ruby Enhanced?
The value of Rubies largely depends on the quality of their color. A deep, pure red color is much more valuable than a lighter pink hue. Heat is used to enhance the red color of rubies. Treating rubies with heat helps improve Ruby’s clarity and gives it an even color.
The changes that occur due to treating a Ruby with heat are permanent, and the Ruby will retain the improved clarity and color without damaging the integrity of the jewel.
Another treatment used to increase the value of a ruby is called fracture filling. Craftsmen use colored lead glass to fill in fractures and defects in the Ruby, increasing the gem’s brilliance and color.
Fracture filling will cause the Ruby to be somewhat less durable, and it may crack when cleaned. Make sure that any gem you purchase comes from a reputable source with all the information needed to take care of the gem.
A third possible way of enhancing the red color in Rubies is diffusion. During a diffusion treatment, a Ruby is heated, and Beryllium is added at very high temperatures. Beryllium can change the color of the Corundum; this method is often used when heat treatment alone does not produce the desired effect.
Treating gems with Beryllium is controversial, as the treatment may only penetrate the Corundum’s outer layer while leaving the gem’s core with the same color as before. These gems will have to be cut in a way that conceals the actual color of the gemstone.
Another reason why treating Corundum with Beryllium is controversial is that the color added was not naturally produced while forming in the earth. The color resulting from the Beryllium treatment may not be uniform.
Treating a stone with Beryllium produces a permanent result, but the gem is made available at a substantially lower price. It is possible to treat a Sapphire with Beryllium and to give it a more orange-like color, enough to be passed off as a Ruby.
Ask whether the gem was treated to enhance the color to assess whether the rock is fairly priced.
A significant factor in a ruby’s valuation is its color’s brilliance. Of course, not all rubies are super expensive. Cheaper rubies are available but will not have the brilliant Red that makes them such a dazzling stone.
Which Shade Of Red Is Most Valuable In Rubies?
Ruby’s most valuable shade of Red is a pure, vibrant red to purple-red. Deep, rich tones of Red are considered more desirable. The shade should not, however, be too dark, so it negatively affects the gem’s brightness.
The colors of cheaper rubies can range from a pinkish red to orange. The lighter the shade and the lower the brightness, the less desirable the stone will be.
The most prized shade for Ruby is pigeon blood red. These rubies have a high saturation of Chromium, giving them a beautiful deep red color while still having a high fluorescence. Rubies with a high saturation contain higher amounts of Chromium and appear to have a more intense, vivid color.
The term “ruby red” refers to a perfectly saturated red with no modifying colors, such as orange or brown. The dark red hue with slight purplish undertones should also have a very high fluorescence. Pigeon blood red is the term that best resembles Ruby Red.
Fluorescence means that the Ruby emits visible light under invisible ultraviolet rays. Fluorescence coupled with a brilliant, pigeon-blood shade of Red makes Rubies particularly expensive.
The clarity, or presence of visible inclusions, will also impact the overall look of a Ruby. All Rubies will contain imperfections; however, the fewer imperfections there are, the higher the gem gets graded.
When determining the value of a Ruby, it is assessed by the 4 C’s: Color, Clarity, Carat Weight, and Cut.
An oval cut is often used because it can show off the Ruby’s deep red color. In larger gems, bigger than 1 .0 carat, a cushion cut shows off its color’s brilliance better.
How To Test Whether A Ruby Is Real
A simple way to evaluate whether a ruby is genuine is to check the integrity of its color. Do a simple test by scratching the Ruby along a hard, smooth glass. Should you notice that some of the colors come off, it is a fake! Rubies which lose their red color are fake.
Where Can You Find The Best Red Rubies?
Myanmar is home to the best quality rubies you can find in India. Burmese rubies are mined here (Myanmar was formerly known as Burma).
Burmese rubies are famous for their beautiful, deep red color, described as a pigeon blood color. These rubies developed their brilliant color because of the high amounts of Chromium in the ground where they are mined.
The highest quality rubies have been known to be sourced from two mines in Myanmar, the Mogôk Valley, and Möng Hsu mines. These sought-after rubies have a beautiful pigeon blood color because of the naturally high Chromium content in the soil.
Famous Red Rubies
The Burmese Ruby Tiara was gifted to the late Queen Elizabeth II by the people of Burma, India. The tiara is set with 96 rubies and was constructed by Gerrard in 1973. It is a widely held belief in India that Rubies protect the wearer from the 96 diseases that may inflict human suffering.
Over the years, Rubies of exceptional quality and beauty have been discovered. These Rubies still mesmerize the world with their beautiful hue and fluorescence:
- Sunrise Ruby
- De Long Star Ruby
- Carmen Lucia Ruby
- Rosser Reeves Ruby
- King Thibaw’s Ruby Hordes
- Liberty Bell Ruby
- Black Prince’s Ruby (Imperial State Crown of Britain)
- Stuart Coronation Ring
- Queen Consort’s Coronation Ring
- Elizabeth Taylor’s Rubies
- The Graff Ruby
- The Burmese Ruby Tiarra
- The Hope Ruby
- The Hixon Ruby
Conclusion
The trace element Chromium in Corundum is responsible for Ruby’s red color. Higher levels of Chromium present will give a Ruby a much more desirable color, with pigeon blood red being the most prized color. Diffusion, heat, and Berylium treatments enhance the red color in Rubies.
