A colorless corundum before receiving its magnificent red color from chromium impurities, Rubies were once known as “the king of gems” and worn by warriors to bring valor in battle. With congress declaring a ban on high quality Burmese rubies in 2008 and the number of synthetics on the market today, consumers are less likely to consider rubies as “the king of gems”.
When purchasing rubies, the most important quality to look for is color followed by cut and clarity. When judging a stone for color, one would want to make sure that it has the darkest color possible. To get an accurate reading on the color, one should always look at the color along the edge of the stone and not straight down the middle. An important note to remember when it comes to the color of rubies is if the ruby appears to be a purplish red color, it is actually not a ruby, but a purple sapphire. Other color concepts to be aware of when buying rubies or any gemstones are color zones and color bands. Color zones are areas of the gemstone that have a lighter or darker color then the general color of the stone. Color bands are streaks of dark or light colors that run through the gemstone.
The next important concept when buying a good quality ruby is the cut of the stone. Cut is important because it brings out the color of a ruby and the more color that it displays, the more beauty and value the ruby will have. There are three important factors when it comes to cut: symmetry, polish, and windowing. Symmetry is the easiest when determining the quality of ruby because one should observe along the outline of the gemstone to see if it is of symmetrical shape. One should also study the ruby while rotating it three hundred and sixty degrees to see if the facet junctions are lined up. Next, under an overhead light, one should look at the surface of the ruby. The presence of little lines appearing like scuff marks signifies wheel marks from the polishing phase. The presence of these marks takes away from the beauty and value of the stone. The last is windowing of the gemstone. Windowing simply means that one can look through the top of a gemstone and see right through to the bottom.
The final factor when buying a ruby is clarity. Clarity is always the last thing to look at when evaluating whether a gemstone is worth buying. Impurities in gemstones cause color and usually with impurities you will have inclusions. Rubies are a category 3 gemstone; meaning that these gemstones will always have inclusions to some degree. In fact, if rubies did not have any inclusions in them then one would have either an extremely rare ruby or a synthetic. When observing the clarity inside a ruby, one should use a 10x loupe and a flashlight for dark field illumination which is transmitted light from either the side or behind the gemstone. When observing the surface of a ruby for any imperfections, one should use a 10x loupe and an overhead light.
Like most gemstones, synthetic rubies have been on the market for over a century. In fact, rubies were one of the first gemstones to be synthetically made in the early 1900’s. During this early stage, flame fusion was the only process used for making rubies. Today, with current advancements in technology, consumers have more of a variety of treatments to choose from including the flux-melt, and pulled or Czochralski. When one is faced with the question of whether a ruby is synthetic or natural, the first characteristic to look for is the cleanliness of the ruby. If the ruby appears to be flawless or free of inclusions, then this is the first red flag that you have a synthetic ruby. The second characteristic to look for depends on what treatment process was used; each method having its own tell tale sign. For instance, flame fusion will display curved striations and gas bubbles, pulled or Czochralski is flawless, and flux-melt displays gas bubbles and inclusions that resemble a fingerprint. When dealing with synthetic rubies or any kind of synthetic gemstone one should always examine them underneath a microscope.
Treatments of gemstones are another process that rubies face in today’s market. With the high demand of quality gemstones, the industry wouldn’t be able to keep up with consumer need without treatments. The treatments that rubies are subject to are fracture filling and heating. Heat treatment is used to enhance the color of the ruby and fracture filling, also called fissure filled, is the process of using a substance that has the same density of the gemstone to fill in surface cracks.
The “king of gems” can still rule the market as long as consumer confidence is not lost by failure to provide the right discloser of treatments or synthetic. If consumer confidence is lost it could causing a collapse in the market.