Blue as the perfect sky, sapphires have been used as protective talismans for centuries. Learn about the versatility of this stone that combines hardness and color variation like no other. Sapphire, September's birthstone, has been the pre-eminent blue gemstone for centuries. Ancient Persian rulers believed its reflection painted the heavens blue. Indeed, its very name in Latin, sapphirus, means blue. While sapphire has become the ultimate blue stone, it actually comes in virtually every color except red (red sapphires are rubies), including colorless and white, and such fancy colors as yellow, peach, orange, cognac, pink, violet, purple and green and all their many shades. In fact, white sapphire has become a popular natural diamond substitute for many people. Moreover fancy color sapphire often provides an alternative to other gems in similar colors that are less durable. It is considered the most important and versatile of the gem families. Sapphire, sister to ruby, is known in the mineral world as corundum, which is a crystal structure composed of aluminum oxide. On the Mohs scale of hardness, sapphire ranks 9, the highest in the gem world after diamond. It is considered very durable, a great choice for rings and bracelets that are prone to knocks. Although sapphire is not as brilliant as diamond, it has striking luster. Like ruby, sapphire may be found in a translucent variety that may display a six-rayed star effect when cut into a cabochon (dome) shape. This type is known as star sapphire, of which there are numerous synthetics on the market. Natural gem-quality sapphire is found in many parts of the world, but the rarest gems are from Kashmir and Myanmar (Burma), most prized because their color is closest to pure spectral blue. Fine sapphire is also produced in Sri Lanka in limited supply, both in blue and fancy color. Sapphire is also found in Thailand, Cambodia, Tanzania, Madagascar, Australia and the United States (Montana). Perfect natural gems--in color and appearance--are very rare and expensive. Controlled heating is commonly used in the trade to produce, intensify or lighten color and/or improve clarity in many gems including blue and fancy sapphire. This allows the trade to bring more, better quality gems to the market. Heat enhancement is permanent and stable. You can clean heated (and non-enhanced) sapphire with soapy water or commercial solvent and a brush. Mechanical cleaners are also safe, except for heavily included gems (filled with fissures). Color is of paramount importance when judging the value of sapphire. The purer the blue of a natural sapphire, the greater the price the gemstone can command. Gems that are too dark or too pale are usually less valuable, but not necessarily less appealing. Beauty is in the eye of the beholder and color preferences are subjective. In recent years technology has perfected the process of heat-treating sapphires--exposing them to very high temperatures to eliminate impurities. In fact most sapphires on the market today have been heat-treated to improve clarity and color. This process is stable and does not affect the value of the gem, except at the highest level of the market. Occasionally, colorless to pale blue sapphire is diffusion treated. This process alters the color of a gem by exposing the surface to certain chemicals (the same used by nature). The treatment is fairly stable, but it is confined to the surface of the gem only. This could create a problem, if the sapphire is ever badly chipped or nicked and needs to be recut or repolished. Diffusion treatment is not the same as heat treatment. Mondera.com only sells natural or stable, heat-treated sapphires of exceptional color in our Gem Store exclusive collection. Additionally, some fancy sapphire is irradiated to produce intense shades of yellow or orange. This process, however, is not very stable. The temporary color produced by this method can quickly fade in light or heat. It is important to buy fine sapphire from a reputable retailer who will provide, in writing, all pertinent information regarding the gem including enhancements and special care notes. A gem's clarity and cut also factor into its cost, as well as carat weight. Better quality sapphires are usually eye-clean with some inclusions under magnification. Sapphire is more available in sizes under two carats, but gems of 5 to 10 carats are not unusual. Sapphire reaches a far greater size than ruby. According to one version of the book of Exodus, Jahweh (God) gave Moses the Ten commandments on tablets of sapphire. Heavenly sapphire has historically been associated with the sacred and divine, guardian of innocence and bestower of truth. This gem was believed to attract divine favor to its owner. It was used as a talisman to protect travelers, ward off illness, and bring peace, joy and wisdom. Sapphire is known as the stone of prosperity. White sapphires have become a popular diamond substitute. It's a great choice for an engagement ring. In fact the engagement ring Prince Charles gave to Diana was a sapphire, not a diamond! Among the most famous sapphires are two of the world's largest. The Smithsonian Institute in Washington, D.C., houses the Logan Sapphire, a 423-carat cushion-cut stone from Sri Lanka that is set in a brooch surrounded by diamonds. The second is the 258-carat bright blue sapphire from the Russian crown, kept in the Diamond Fund in Moscow. In addition to its place as September's birthstone, sapphire is a recommended gift for couples celebrating their fifth or 45th wedding anniversary. According to Hindu legend, sapphire was also the zodiacal gem for Taurus (April 21-May 21); in the Arab tradition it represents Gemini (May 22-June 21).