Sapphire is the name given to the non-red, gem quality variety of the mineral corundum—the second hardest substance on earth, just below the diamond. Corundum itself is not a particularly rare mineral, with most being translucent to opaque and heavily included, and useful mainly as an abrasive for industrial purposes. Gem quality corundum, on the other hand, is extremely rare.
Blue is the classic and traditional color of sapphire—the name sapphire itself comes from the Greek word for blue. Corundum that has trace amounts of iron results in a blue sapphire, and chromium impurities result in a pink or red color, with red corundum well-known as its own colored gemstone, the ruby. In addition to the blue sapphire and the ruby, the corundum family of colored gemstones includes so-called “fancy sapphires:” corundum with trace amounts of titanium, copper, or magnesium can result in yellow, orange, or green sapphires respectively.
Sapphires are found in only a few locations in the world, including the most famous blue sapphire deposits in Kashmir, Burma, and Sri Lanka. Recent deposits found in Madagascar, Tanzania, and Australia are considered today’s most important deposits.
Sapphires are evaluated based on their color, clarity, size, and cut, but the most important factor is generally their color. Color is broken down into three components: hue, saturation, and tone, with “hue” being commonly understood as “color.” Blue sapphires exhibit various mixtures of primary hue (blue), and secondary hues (most commonly purple, violet, and green), as well as various tonal levels (shades) and levels of saturation (vividness).
Judged mainly on the purity of their primary hue, blue sapphires with up to fifteen percent violet and purple secondary hues are generally regarded as fine quality, but any amount of green as a secondary hue is considered a detriment to the stone’s overall quality. Gray is a common saturation modifier, but it generally reduces the saturation or brightness of the hue and compromises the impact of the colored gemstone.
Fancy Colored Sapphires
The presence of other minerals in corundum leads to sapphires of nearly every color in the rainbow. While blue sapphires get their color from iron and titanium, violet stones owe their color to the presence of vanadium, and pink sapphires are tinted by chromium. Yellow and green sapphires are fairly common, though most yellow sapphires are naturally more lightly colored. Combinations of iron and vanadium can lead to orange stones.
One particular pinkish-orange sapphire is known as “padparadscha,” from the Sinhalese word for the “lotus blossom,” which has a pinkish salmon color. Originally found in Sri Lanka, padparadscha sapphires have also been found in Vietnam and parts of East Africa, though they remain quite rare. Treasured by connoisseurs, padparadscha sapphires are extremely valuable, even though there is no uniform standard for the color.
Star Sapphires and Color Changing Sapphires
Star sapphires exhibit a phenomenon known as asterism. Tiny needle-like rutile inclusions intersect in the crystal structure and align to cause a star shaped pattern in the top of the sapphire. These colored gemstones are typically cut en cabochon, with the center of the star near the top of the dome.
When viewed with a single overhead light source, a six rayed ‘star’ shaped pattern appears. Asterism can appear in any colored sapphire, and is typically valued by its strength and contrast with the color of the stone. Occasionally, twelve rayed stars can be found, due to two sets of inclusions.
Some rare sapphires, called color-change sapphires, manifest different colors in different kinds of light. Some color-change sapphires appear blue in outdoor light and purple under incandescent, indoor light, and some appear greenish in daylight and reddish-violet in incandescent light. The color-change phenomenon is due to the interaction of the different light’s wavelength and metal impurities in the sapphire itself. The actual color change can be judged as weak, moderate, or strong, and the strength of the stone’s color change is the most important factor affecting the value of the colored gemstone.
Sapphire History and Lore
Archaeological evidence reveals that the very earliest sapphires most likely came from Sri Lanka, traveling through the Middle East to the Mediterranean cultures and eventually to Europe during the Roman Empire. The earliest sapphires were simply polished rounded stones, sometimes drilled and used as beads for necklaces and bracelets, or set en cabochon. Surface faceting of sapphires does not appear until after the 16th century.
Traditionally, the sapphire has symbolized truth, sincerity, nobility, and faithfulness. The kings and queens of ancient Greece and Rome believed sapphires could protect them from envy, and many believed wearing sapphires was an antidote against poison and would shield them from disease. Sapphires have been worn by the clergy since the Middle Ages, the blue of the stone thought to emulate the pure blue sky of heaven.
Magical properties have also been ascribed to the sapphire. Once used to banish evil spirits and negative spells, sapphires were also thought to guard against poisonous creatures, and some believed that they could increase communication with angels and spirit guides. One curious belief about color-changing sapphires was that they had the power to detect female virtue, though the “‘test” was often manipulated. If the owner of the stone wished to prove a woman’s virtue, he would have her wear it in only daylight, but if he wished to prove the opposite, he would time the test so that it began in daylight and ended under candle or lamp light. The stone would change color, supposedly indicating her lack of virtue.
Sapphires today are often heat treated to improve their color, clarity, and overall appearance. Although this treatment has been known since antiquity, it was perfected in the last half of the twentieth century, and most sapphires available today are heat treated. The colored gemstones are heated to temperatures between 500 and 1800 degrees celsius for several hours, enhancing their clarity by reducing or eliminating needle-like rutile inclusions. Heat treatment is considered stable and permanent, and is accepted in the industry when disclosed. Untreated sapphires of exceptional clarity and color are rare indeed, and command the highest prices.
Other treatments include lattice diffusion treatments and fracture filling. Lattice diffusion is a process in which chemicals and heat are used to diffuse an element, like beryllium, into the sapphire to change its color at the molecular level. Fracture filling is a treatment that uses resin or other fillers to improve transparency and clarity, but it is neither stable nor permanent. Both of these treatments are not widely accepted in the industry and should always be disclosed as they greatly affect the value of the sapphire.
How to Sell Your Sapphire Jewelry
If you own expensive sapphire jewelry that you would like to sell immediately for a generous cash offer, please contact Diamond Estate Jewelry Buyers today. We are widely recognized as the best place to sell sapphire rings, earrings, and necklaces of exceptional quality, including collectible sapphire jewelry from Tiffany & Co., Harry Winston, Cartier, Van Cleef & Arpels, Chopard, and other luxury brands.