When you hear people talk about the King of Precious Gemstones it is the Ruby. In the ancient language of Sanskrit the Ruby is called ratnaraj, which translated means the King of Precious Stones. Rubies have been significant in history as a prized and valuable gemstone. Over the centuries and presently today it is still one of the most precious gemstones, not only due to its beauty, but also its durability. Ruby is a 9 on the Mohr scale, which makes it well suited for daily wear.
There are considerable variations in a Rubies, Cut, Color, Clarity and Carat Size that can impact cost. Prices can range from the 15.97 Carat sold at an international auction for $3,633,000 in 1988 to everyday prices you will see in most jewelry shops and on-line gemstone stores. Like most gemstones it's the size and quality that dictate the value and ultimately the price you pay.
Lets take a look at the Color, Cut, Clarity and Proportions and see how they impact the value of this gemstone.
Color. The color of Rubies can range from orangey red to purplish red. The most valuable Ruby is a vibrant red to a slightly purplish red hue. The saturation of the color is equally important, as the most valuable Ruby will have a vivid saturation. Another consideration is tone as it should be medium to medium dark, if it's too dark then it will impact the gemstones brilliance. If the gemstone is too light it will look pink and then it cannot be called a Ruby, and must be classified as a Pink Sapphire. Most sellers would like borderline colors of pink/red to be classed as Rubies as they are more valuable. If you are purchasing a more expensive Ruby its important to have it graded by a reputable laboratory, such as GIA or EGL to have the color authenticated against color master stones.
Cut. Today fine quality Rubies over 1 carat are rare, but commercial quality Rubies are readily available. The most common cuts for Rubies are Ovals and Cushions with brilliant cut crowns and step cut pavilions. You will find Round, Trillion, Emerald and Pear in smaller sizes but they are rare in larger sizes with higher qualities. Cutters will try to cut the gemstone to minimize the orangey red color, due to the Pleochroism (different colors of the gemstone depending on which way it is observed) to increase the value.
Clarity. Most Rubies contain some inclusions as flawless Rubies are very rare, expensive and usually belong to collectors. Some of the inclusions you might see are silk, needles, included crystals, fingerprints, growth and color zoning, and color banding. There are different grading scales available throughout the world but the most commonly used one is from the Gemological Institute of America (GIA). The gemstones are graded into 3 Types and each Type has the following grades Eye Clean, Slightly Included, Moderately Include, Heavily Included and Severely Included. Corundum is a Type 2 and if you have the opportunity to purchase one that has a clarity rating of Eye-clean you will have the highest clarity available.
Proportions. Symmetry in any gemstone is important as you will find many commercial Rubies will have variations in its symmetry when looking face up. These include out of round, uneven lobes in Heart shapes, uneven wings in Marquise cut, uneven shoulders in Ovals. The other area of focus is the pavilion, as cutters will add weight with a resulting pavilion bulge, but this adds nothing to the beauty of the Ruby. Brilliance can be affected by shallow pavilion causing large windows or by offset pavilions. The other important grading characteristic that is important is finish; you should not be able to see polishing lines, scratches, pits or abrasions on the Rubies surface.
When purchasing a Ruby you can use these guidelines for your purchase, but as with all gemstone purchases you will probably have to balance carat, clarity, cut, and color to meet a price point you are willing to pay.
Derek Parnell is a Graduate Gemologist (GIA) and can be reached at Jewels by Truros