Few gemstones have the visual impact of a ruby, the rich red color catching the eye from the instant that it is seen; it is the color which defines a ruby. Any stone either slightly too dark, or bordering on pale and pink is regarded in the jewelry trade as a pink or purple sapphire, even though there is more latitude on color outside the USA.
This precious gemstone gets its name from its color, the Latin for red being ruber. Chromium is the impurity that provides the richness of color and the value of a ruby is largely determined initially by that color. Ruby is particularly hard on the Mohs scale, behind only diamonds and moissanite amongst natural gems. It is an aluminate with those chromium impurities. All natural rubies have these impurities with the rutile imperfections creating a needle effect.
The value of a ruby is primarily based on the purity of color. In the case of rubies, it is the red hue with secondary hues varying from purple and orange through to violet and pink, purple perhaps being the hue that best reinforces the strength of the red. Such a ruby set in gold as it appears even richer in color because of the yellow gold neutralizing any blue.
Although the description of pigeon blood red is hardly an attractive term, it is a designation that has become the norm in describing a valued ruby. A deep, pure vivid red is the most prized color . Whilst dark pink and brown content are acceptable as colors of rubies, the value of such stones drops dramatically in relation to the pigeon blood red. Poorly colored Ruby is common.
Clarity will usually play a limited part in the valuation of a ruby. It is almost impossible to find a ruby that needs no treatment; the color is created by impurities. Only the best rubies are faceted and these are the ones with minimal inclusions. The common inclusions are in the form of white wisps of rutile, the white obviously diminishing the richness of the red.
The most important factor about the cut is not to lose too many carats as the best of rubies are so rare and valuable. As a result, cuts are often imperfect. This is because the gems cutter may try to avoid diminishing the overall value by preserving size versus going for the prefect cut.
To find perfection in the cut, it may sometimes mean a loss of up to 60% of its weight, a very costly exercise. That said, the best cut displays a ruby in all its glory, with light reflecting from every facet. It is much more common however to see a cut with uneven facets and less sparkle. An indicator of a poor cut is if you can see through the ruby and is relatively less valuable as a consequence.
Ruby Carat weight
The cost per carat of a ruby varies significantly based on its size. It increases dramatically with the larger stones given that they are so rare. Very small rubies are common; however, there is a premium in the price, in addition to carat weight, whereby the rarity of the stone is factored in. For example, the price per carat can increase by much as tenfold for stones larger than 3 carats.
It is taken as a given that most rubies are treated; they almost always have inclusions and the heat treatment improves color and clarity, and in the poor quality stones, fissures on the surface of the stone are filled with glass or synthetic crystal to enable use of the ruby in jewelry. It is important that the treatment to improve the ruby is permanent; anything less will certainly reduce the ruby’s value. Anything that is too clear will immediately arouse suspicion that it is synthetic; perfect clarity and rubies do not often go together.
Whenever a “perfect ruby” was found historically, given they are so rare, there are only a few places where it can ultimately end up, a museum, royal jewelry collections or the home of the extremely rich. One of the most famous rubies resides in Washington DC at the National Museum of Natural History; a 23 carat ruby set with diamonds in a platinum ring, a gift from Peter Buck, a wealthy businessman in memory of his late wife. The stone is believed to have been found in Burma in the 1930s.
An even bigger stone, 40 carats was featured by the famous London jewelers, Garrard’s in their 2007 website. The recent auction of Elizabeth Taylor’s jewelry which, rose $115m including a diamond and ruby ring that sold for over $8m.
Burma was the main source of rubies for most of history but their distribution is now widespread throughout many parts of Asia, countries such as Tanzania and Mozambique in Africa and large deposits have now been found in Greenland.
Formula : Al2O3:CR
Symmetry : Trigonal
Crystal : Hexagonal prisms.
Specific gravity : 4
Mohs scale hardness : 9
Ruby Myths and Legends
Trade in rubies began centuries ago; there are references to the Trade in the days of the Silk Road and it could have been as early as 200BC when the trade first began. They remained gemstones that were highly prized throughout Asia through the Centuries ad that value has subsequently been recognized throughout the World. Legend has it that Ruby’s protect its wearer from poor health and misfortune. In ancient Burma, Warriors believed that Rubies gave them an aura of invincibility on the battlefield.
Whatever the reason, be it mystical healing properties or its gorgeous red color, a ruby is a valued addition to any gemstone jewelry collection.