Let's talk today about sapphires. The birthstone for those who are born in the month of September has a variety of colors and is known in the jewelry world as corundum. According to the MOHS hardness table, sapphire is rated as a 9, which is second only to diamonds.
Sapphires have been priced for their beauty since 800 BC, when they were considered the symbol of the heavens. Legend has it that the earth rested on a sapphire and the sky reflected its color. It was also believed to be the symbol of truth.
Sapphires have been found in riverbeds in sizes from 1 carat to 10 carats. Generally they originate from Burma, Sri Lanka, Thailand, and Australia. Available in many colors, sapphires may be yellow, orange, green, pink, colorless, purple, black, and violet. Often they are heat treated to enhance their color by raising the temperature up to nearly their melting point, which is approximately 1600 degrees Celsius. This form of treatment is done regularly in the jewelry industry and is permanent, so no need to be concerned if yours has been treated this way.
Another form of treatment or enhancement that is commonly done to sapphires includes dye impregnation, which is the coloring of a stone with dye under pressure. This form of treatment is not necessarily permanent and should be avoided if at all possible.
Inclusions and color zoning are a common occurrence in sapphires and unless extreme in either case, does not impact the beauty of the stone. Color zoning is when the sapphire displays dark and light zones of color running parallel to each other. Inclusions are the presence of foreign materials inside the gemstone that are trapped during the crystal growing stage. Although inclusion in sapphires effect the value of the stone, it is not as reprehensible as being present in diamonds. Inclusions are identifying characteristics, which also proves the genuine nature of the gem.
There are several synthetic manufacturers of corundum gaining popularity today. The process is generally taking seed crystals of sapphires and placing them into an ideal environment in an autoclave-like oven that is under tremendous pressure inside, along with a growing agent called flux. After 6 months or longer the crystal formations, which have now grown, are removed and cut into faceted gemstones. These sapphires rival the naturals and in some cases, special equipment is needed to identify one from the other. It is important to note that the term synthetic here means having the identical chemical composition, but not grown naturally, or needing man's intervention. The resulting sapphire is a genuine sapphire, but not a natural one. This process is far removed from the flame fusion process or other simulated gemstone growing types, which produce a stone that has the same color, but not the identical chemical composition. This difference is extremely important for the consumer to understand so as to know what type of value you are receiving when making a purchase since the synthetic is much more valuable than the simulated stone, which in some cases may be glass or even plastic. Remember that synthetic is having the identical properties of the natural, but grown with man's intervention. The logical comparative is the pearl. Natural pearls occur when a grain of sand or some other foreign element gets into an oyster and irritates it to secrete a coating around it called nacre. Cultured pearls are the same basic elements, but with man not nature supplying the foreign element, which is usually a glass or plastic bead. It is nearly impossible to identify the difference between the two without X-rays or drilling.
Many believe that the darker the sapphire the finer the quality, however this isn't always the case. Australia has always been known for their fine quality sapphires, yet because the veins they are presently mining are old and very deep, the color is very dark on most of the rough. There have been many times that the stones have been almost black, and that is not what is considered fine quality by any standard. A fine quality sapphire should be a rich royal blue which is translucent and brilliant. In the case of Ceylon sapphires, which come From Sri Lanka, a lighter shade of blue is very acceptable. The reason these sapphires are lighter in color is due to the fact that they are newer deposits and the heat from the core of the earth has not had the opportunity to darken them yet. This Ceylon sapphire gemstone is quickly growing in acceptance and prices are rising as supply is limited.
Man has tried to duplicate what happens in nature to enhance the gemstones that were inferior in the rough. In many cases, man has actually exceeded nature in his ability to make a beautiful gemstone from a rough unattractive crystal sapphire.
Sapphires have also been a gemstone that many have purchased as a hedge against inflation. The typical investment sapphire is over 5 carats with a cashmere or cornflower blue color that is nearly free of any inclusions and is brilliantly cut proportionately. It is recommended that if you are interested in investment grade sapphires to purchase only certified sapphires from a reputable dealer who is knowledgeable, established, and honest. The author recommends only AGS (American Gem Society) certifications to insure reliable and accurate grading information. With the proper guidance, an informed investor can realize strong profits when investing in fine quality sapphires given enough time for the investment to grow.