Evaluating Rubies and SapphiresBuying a gemstomestone online can be such a difficult thing. But that statement is true about buying a gemstone from a retail store or expert jeweler especially when you do not know what to look for.We at Mogok Rubies & Sapphires Ltd will attempt to shed some light on the subject.
The 4 C’sBrowsing through our website you would have noticed that some smaller rubies and sapphires are much more expensive than some bigger ones. This is not a misprint which leads to rule number one weight (size) is not everything. As a matter of fact it may account for about 10% of the value placed on the gemstome.
Carats - weight (size) is measured in Carats(ct), the first C. One gemstone carat is 200 mg, so there are 5 carats in 1 gram. Do not confuse carat, a measure of weight, with karat, a measure of gold purity. Carat size is the last determining factor for the price of a ruby or sapphire.
Cut - Cut and shape are a little different, cut referes to the way the ruby or sapphire is trimmed to get the most out of the gemstome’s color. To get a rich, dark color a gemstone may be cut deep, to get a light, brillant color it may be cut more shallow. The way a gemstone is cut on the Crown or face may be differrent from the way it is cut on the Pavilion or bottom. This is referred to as a Mixed Cut and is very common. Round shaped rubies and sapphires are more rare than Ovals. Cushion, Pear, Heart, and some others shapes are even more rare specificly for the Mogok, Myanmar rubies and sapphires.
Well cut stones of good symmetry, attractive design, and fine polish are more prized than poorly cut stones. Unfortunately, many higher priced stones, such as rubies and sapphires, are often poorly cut in order to maximize weight at the expense of appearance.
When evaluating Cut look for scratches, this will reduce the price, as well as uneven cuts and divets, usually made to re-shape the gemstone.Cut can account for 10-15% of the value of a ruby or sapphire.
Clarity - transparency, is very important. Unlike diamonds inclusions do not impair the quality of a ruby or sapphire unless they decrease the transparency of the stone or are located right in the centre of its table. On the contrary, inclusions within a ruby or saphhire could be said to be its fingerprint, a statement of its individuality and, at the same time, proof of its genuineness and natural origin.
Gems with fewer and smaller inclusions are more highly prized than those with more numerous and larger inclusions, unless the inclusions contribute in a positive manner to the appearance of the stone.
Clarity in a ruby or sapphire accounts for 25-30% of the value assigned. You can safely judge clarity buy looking at the stone and being able to see through it. Seeing inclusion through a jeweler’s loop is good not seeing any should raise a flag. Chances are it has been enhanced through heat treatment.
The Big C - Color - that is depth and purity of color, counts for approximately 50% of the value of the ruby or sapphire. Vivid, saturated colors are more highly prized than subdued or grayed-out colors. Deeper colors are more highly prized than lighter ones, unless the depth of color is so great as to make the stone appear blackish. The best color for any gemstone should be obvious from several feet or even several yards away. For example, a ruby should be intensely red from across a room, and a blue sapphire should be obviously blue, not black.
General Pricing InformationRubies are the most valuable members of the corundum family. Large gem quality rubies can be more valuable than comparably sized diamonds and are certainly rarer. There is a relative abundance of smaller, (1-3 carat,) blue sapphires compared to the scarcity of even small gem quality rubies, making even these smaller stones relatively high in value.
Stones of Burmese(Mynamar) origin generally command the highest prices. High value ruby rough is tightly controlled and rarely makes its way to custom cutters. Occasionally, such native stones are recut to custom proportions, albeit at a loss of weight and diameter. Custom cut and recut stones are usually more per carat.
Stones that have been enhanced in color or clarity by artificial means are worth considerably less than unaltered stones of the same appearance. You should know that all the gemstones shown on our website have NOT been heat treated or enhanced in any way!
Burmese(Myanmar) stones in 1/2 to 1 ct sizes with slightly purplish red color and light inclusions range from $300 to $3000/ ct, for example. The price survey done by the International Gem Society reports that clean, top color gems in the 1/2 to 1 ct size range are being sold, retail, on the Internet with a range of $1000 - $3000/ct.