Sapphire is the blue sister of ruby. Ruby and sapphire are the same material, the mineral corundum, and the second hardest gemstone after diamond. Red corundum is known as ruby, while all other colors are referred to as sapphire. While blue is the classic sapphire color, sapphire is actually found in a wide range of colors.
Blue is the most famous of the sapphire colors. The prized Kashmir and Burmese sapphires have a deep blue that is intense and velvety. These sapphires are not often seen on the market today. Sri Lankan and Madagascar sapphires are the most common today, with a wide range of colors from light sky blue to dark blue. Other producers of blue sapphire are Australia, Tanzania, Thailand, Cambodia, and the USA (Montana).
Colorless corundum is rare as faint shades of color are nearly always present. Many small white sapphires used in inexpensive jewelry are synthetic.
Purple sapphire is rare, but found in Sri Lanka and Tanzania. Iron and titanium impurities together may cause the purple hue of the stone.
Much yellow sapphire is on the lighter side. Heat treatment can produce a more intense yellow golden color, and beryllium-treated sapphire may be a brilliant yellow. These stones are found in Sri Lanka, Thailand, Australia, Tanzania and Madagascar. The yellow color is caused by traces of iron in the stone.
Padparadscha is the Sinhalese word for a Sri Lankan lotus flower. This very rare sapphire color should have a pink and orange color simultaneously. Color, brilliance, size and clarity will determine the value of these stones. A true padparadscha will always have a hint of pink.
Many sapphires that appear green consist of fine alternating bands of blue and yellow sapphire, which may be visible under the microscope. Green sapphires are found in Thailand, Sri Lanka, Australia, and Madagascar.
With blue sapphire, the most popular color, the intensity of blue as the most important factor. For example, you may have a huge stone of many carats, but if the color is a washed-out, weak blue, then the value of the stone will be lower. Look for a stone that has an intense, rich blue without being dark or inky. Overall, sapphires that are too dark or too light in color are valued less. However, light blue sapphires often have a brilliance that is rarely found in the darker stones.
Sapphires look best viewed with fluorescent light or daylight. Incandescent light is more red, and sapphires look less attractive in this lighting.
Sapphire tends to be cleaner than ruby. Look for stones that are eye-clean. This means no inclusions that are visible to the naked eye. Actually, extremely fine silk throughout the stone can enhance the value of some sapphires. The famous sapphires from Kashmir have a velvety blue color which is caused by this fine silk. This silk is needed for the star effect in star sapphire, however, too much silk weakens the color, making it appear undesirably grayish.
Various shapes and cutting styles are common with sapphires. Ovals, cushions, and rounds are seen, as are other shapes, such as the heart or emerald cut. Round stones can command a small premium. Cabochon-cut sapphires are also common. Used for star stones, the best cabochons are somewhat transparent, with smooth domes of good symmetry.
Sapphire location and deposits
Sapphires come from Thailand, Sri Lanka, Madagascar, Tanzania and Australia. The United States, Cambodia, Nigeria, Kenya and China also produce some sapphires. Perhaps the most famous sources for sapphires are the Kashmir region of India, and Burma. Discovered over 100 years ago, the Kashmir sapphire has a lovely, velvety blue color prized by gem lovers. Burmese sapphires can also be fine, but like the Kashmir region, these two areas today produce very little material.
Today Sri Lanka and Madagascar produces most of the fine sapphires on the market. You can find a wide range of beautiful blues, from soft sky blue colors to deeply saturated hues. In addition, the Kanchanaburi region in Thailand and the Pailin region in Cambodia are renowned for deep blue sapphires. Tanzania, an old producer of sapphires in other colors, is now starting to produce blue sapphire from new deposits in the south.
Common Sapphire treatments
The most common treatment for sapphire is heat treatment. Stones are heated (generally before they are cut) to between 1700 to 1800 degrees Celsius (3100-3300 degrees F) for several hours. Most sapphires today are heated, and the stones of rich blue that are not heated can command enormous prices in today’s market. Some blue sapphires may also be diffusion treated, though this treatment is more common for star sapphires. Beryllium treatment is now being used to produce stunning orange and red colors that were once rarely seen. All sapphire treatments should be fully disclosed by any reputable dealer.
Large sapphires are rare and often attract fame and myth. The largest star sapphire is the Star of India at an amazing 536 carats. Discovered about three hundred years ago in Sri Lanka, the Star of India was donated to the American Museum of Natural History by the financier J.P. Morgan. Later the infamous burglar Jack Murphy, Murph the Surf, stole the stone. Its recovery two months later only added to its fame.
The 423 carat Logan Sapphire is displayed in the Smithsonian Museum of Natural History. It is the largest faceted sapphire on public display and perhaps the largest blue sapphire known. This egg-sized, cushion cut stone from Sri Lanka is set in a brooch surrounded by 16 carats of diamonds. It was donated by Mrs. John A. Logan to the Smithsonian Institute in 1960.
Other famous sapphires include the Midnight Star, a 116 carat black star sapphire. The intensely blue 330ct. Star of Asia can be found in American Museum of Natural History. Also, the English Crown Jewels contain two famous sapphires: the St. Edward’s and the Stuart Sapphire (104 carats).
Color: Blue, colorless, pink, orange, yellow, green, purple, black
Chemical composition: Al2O3, Aluminum Oxide
Crystal system: (Trigonal), doubly pointy, barrel-shaped, hexagonal pyramids, tabloid shaped
Hardness: 9 (Mohs scale)
Specific gravity: 3.95 – 4.03
Refractive index: 1.762 – 1.788 +0.08 -0.04
Optical character: Uniaxial
Color of streak: White
Absorption spectrum: Blue, Sri Lanka: 471, 460, 455, 450, 379; Yellow: 471, 460, 450; Brown: 471, 460-450
Fluorescence: Blue: none; Colorless: orange-yellow, violet
The coloring agents in blue sapphire are iron and titanium and in violet stones, vanadium. Small amounts of iron impurity will result in yellowish and greenish stones. Chromium will produce pinks, and iron and vanadium will produce orange tones. Rutile needle inclusions will result in a silky shine to the stone. If these needles are aligned in the same direction, then this causes the six-rayed star sapphire affect. These clumps of needles reflect the light in sixty-degree angles.
The Sapphire zodiac, myth & legend
Sapphire is the birthstone for those who are born in September. As for the Zodiac, it is regarded as the stone for the Taurus. If a Taurus wears a sapphire, it will protect one from and cure one’s mental disorders.
Through history, sapphire symbolizes truth, sincerity, and faithfulness in relationships, and to bring peace, joy and wisdom to the wearer and owner. In the past, the sapphire was also believed to be a talisman that would protect you against evil spirits and other unsavory creatures of the night. The ancients regarded star sapphires as a powerful talisman protecting travelers and seekers. They were so powerful, they would continue protecting the wearer even after being passed on to another person.
Abbes Hildegard von Bingen (1098-1179) chronicled the healing powers of gemstones in her book Physica. According to her view, gemstone are formed through the powerful combination of water and fire, therefore they hold powers corresponding to these phenomena. She also believed that each stone had a certain, divine blessing from God. She said this about sapphire: Who is dull and would like to be clever, should, in a sober state, frequently lick with the tongue on a sapphire, because the gemstone’s warmth and power, combined with the saliva’s moisture, will expel the harmful juices that affect the intellect. Thus, the man will attain a good intellect.