Sapphire is an aluminum oxide. Its colour varies from very light to dark blue to violetish-blue, bluish-green, yellow, slightly reddish-orange, brown, nearly opaque black, colorless, pink, violet and the pinkish-orange padparadscha (lotus flower).
Ceylon sapphires are part of the Corundum gem family and are second only to diamonds in hardness. This strength makes them an excellent choice of jewelry because of their durability. The sapphires mined in Sri Lanka are known for the unique color they produce. Because Ceylon sapphires occur naturally, the color of the stone varies.
Often, sapphires used in jewelry are heat-treated or given chemical diffusion to enhance their color, these enhancements are permanent.
Sapphire is the birthstone of September
Treatments - Sapphires can be x-rayed to intensify their colour. Natural sapphires undergo heat and diffusion treatments in Thailand. With the first method, sapphires with latent chemical components for good color are "ripened" to a desirable color through heating. In diffusion treatment, sapphires that lack the components for good color are placed in a bath of colouring oxides that penetrate the outer layers of the stone. Treatment of blue stones is permanent.
History - According to an ancient Persian legend, the earth rested on a great sapphire whose reflection was seen in the sky. The stone also appears in the Promethean legend. Prometheus was chained to a rock by Zeus for having stolen fire from the gods. After being rescued by Hercules, a link of the chain remained on his finger, and attached to it was a piece of rock. Zeus agreed to grant Prometheus his freedom if he wore the link as a reminder of his sin. Later a ring set with a sapphire replaced the link and stone. Sapphire symbolizes truth, sincerity and constancy. It was believed to protect the wearer against capture by an enemy, and to win the favor of princesses. It also protected against poison. It was said that if a poisonous snake were put in a vessel with a sapphire, the rays from the gem would kill it. The name sapphire originally comes from Sanskrit. It became sappheiros in Greek, meaning blue. Before the value of sapphire was known to them, villages in the Zanzkar mountains of Kashmir (India) used the gem as a flint to start fires.
The Ceylon Blue Sapphire is known for its beauty – possessing the glorious cornflower blue shade – as well as for being one of the few sapphires in the world that can be sold as a completely natural stone without heat treatment. The blues aside, Ceylon sapphires also come in beautiful hues including pink, yellow, orange, green, purple, lavender and of course, the inimitable padparadscha sapphire – named after the lotus flower. All these highly marketable qualities of Ceylon sapphire has created brand recognition world wide - a brand not created by the producers of the stone, but by the sellers and consumers.
Sapphires that show a star-like light effect are called star sapphires; the most famous star sapphire from Sri Lanka is displayed in the Museum of Natural History in New York. Star sapphires or star rubies display a star-like marking and this effect, commonly known as asterism, occurs when light falls on the cut stone, cut in the cabochon form, and three rays appear giving a six-point star. However, stones with six rays have also been known to occur.
Lastly, there is milky corundum, a white opaque form of corundum also called geuda, which for many years was regarded as useless and discarded, often ending up lining fish tanks in some gemstone merchant's house. This happened until dealers in Thailand learned to heat-treat geudas to change the colour of the stone from an unattractive cloudy grey-white to a bright, sparkling blue. They completed the work nature began and ended up with a blue sapphire - of much greater value than a useless pebble. The color of heat-treated blue sapphires are stable and the chemical composition of the stone is that of a sapphire, although prices are lower than for a similar quality stone with natural color.
Choosing a Sapphire
The most famous sources for sapphire are Kashmir and Burma, (now known as Myanmar). Kashmir sapphire, which was discovered in 1881 when a landslide in the Himalayas uncovered beautiful blue pebbles, has a rich velvety colour prized by connoisseurs. Burma sapphires, from the same region that produces fabulous rubies, are also very fine. However, today, these two sources account for a very small quantity of the sapphire on the market.
Most fine sapphire on the market today comes from Sri Lanka, which produces a wide range of beautiful blues from delicate sky blue colors to rich saturated hues. Kanchanaburi in Thailand and Pailin in Cambodia are renowned for deep blue, even colors. Two relatively new mining localities are showing promise: Madagascar, which has produced some exceptionally fine stones in small sizes but has no organized mining yet, and Tanzania, which has long produced sapphire in other colours but is starting to produce blue colors as well from a new deposit in the south.
The most valuable sapphires have a medium intense, vivid blue colour. The best sapphires hold the brightness of their colour under all different types of lighting. Any black, grey, or green overtones mixed in with the blue will reduce a stone's value. In general, a more pastel blue would be less preferred than a vivid blue but would be priced higher than an overly dark blackish-blue color. As with all gemstones, sapphires, which are "clean" and have few visible inclusions or tiny flaws are the most valuable.
Sapphires are most often cut in a cushion shape - a rounded rectangle - or an oval shape. You can also find smaller sapphires in round brilliant cuts or a wide variety of fancy shapes, including triangles, squares, emerald cuts, marquises, pear shapes, baguette shapes, cabochon cuts and smooth domes.
