Types of Sapphire

by Ardamun Ramdeva

It is estimated that over 90-95% of the sapphires in the market today are heat-treated. Sapphires are also treated by Irradiation. Pale yellow sapphires are irradiated to change them to golden yellow. This process is not acceptable as it is not stable and colors, so produced, fade in light and heat.

Summary: It is estimated that over 90-95% of the sapphires in the market today are heat-treated. Sapphires are also treated by Irradiation. Pale yellow sapphires are irradiated to change them to golden yellow. This process is not acceptable as it is not stable and colors, so produced, fade in light and heat.

Sapphires - Gemstones of the Skies

Blue Sapphire RingSapphire belongs to the mineral family of Corundum. When you think of Sapphire, you normally think of Blue Sapphire. Actually, natural sapphire comes in a variety of colors, including red. We know red sapphire, more commonly, as Ruby. Sapphires of all other colors are prefixed by their colors, such as Blue Sapphire, Yellow Sapphire, etc. The other colors can be pink, orange, yellow, golden, purple, green, and white. Another sapphire is the exotic orange-pink known as the Padparadscha Sapphire. The major sources for various colored sapphires are Burma (Myanmar), Madagascar, Sri Lanka, Thailand, Australia, East Africa, and the United States.

There is a theory that heating sapphires adds to its value by enhancing its color and clarity. It is estimated that over 90-95% of the sapphires in the market today are heat-treated. Sapphires are also treated by Irradiation. Pale yellow sapphires are irradiated to change them to golden yellow. This process is not acceptable as it is not stable and colors, so produced, fade in light and heat.

Types of Sapphire

Sapphires are extremely hard and durable, with a hardness of 9 on the Mohs' scale. It is the hardest gemstone except diamond, which has the hardness of 10. Corundum, to which family Sapphires belong, is a natural mineral - Aluminum Oxide. It is the rare small traces of titanium, iron, chromium and vanadium, which create the various colors in sapphires. The rarest of all colors is the orange-pink of the Padparadscha Sapphire - a Sinhalese (from Sri Lanka) word meaning 'lotus flower'. The main property of Padparadscha sapphire is that it should display the combination of both the colors, orange and pink, and in such a way that it should be difficult to see where one color ends and the other starts. Experts find it difficult to agree on the exact ideal color of Padparadscha sapphire.

Padparadschas as a collector item, are hot and snapped up as soon as they appear. Tone and place of origin are crucial factors in determining what is true Padparadscha sapphire. Experts believe that the tone should be light to medium hues of sapphires from Sri Lanka (Ceylon). It has been seen that some sapphires from Tanzania and Madagascar have been sold as Padparadschas, but they had too much of orange-brown to be classified as Padparadscha. The price of the unheated Padparadscha from Sri Lanka ranges from $4,000 to $10,000 per carat.

blue sapphiresBlue Sapphires are the most well known of all sapphires. It is usually just known as sapphire, without any color preface. The finest of these come from Kashmir - in India, Mogok - in Burma, and Sri Lanka. Blue sapphires are considered the perfect and exceptional sapphires. Sapphires look fantastic under one light condition or the other, but blue sapphires look magnificent in all light sources. One of the largest blue sapphires known is the Logan sapphire, weighing a massive 423 carats. This flawless gemstone, of Sri Lankan origin, has a rich blue color and is the second largest blue sapphire known. Cornflower blue and deep blue are the two popular choices of blue sapphires. The intensity of blue determines its value. The most expensive blue sapphire ever sold was the 62.02-carat Rockefeller sapphire at $48,871 per carat.

ping sapphirePink Sapphire is the second most valuable sapphire. A pure vibrant and vivid pink color makes these gemstones exceptional. It is difficult to decide where it stops being pink sapphire and transits into ruby. The American Gemological Laboratories (AGL) has a grading system that draws a line between pink sapphire and ruby. At that particular point, if the stone is redder, it is ruby; otherwise, it is graded as pink sapphire.

Yellow, Golden and Orange sapphires are relatively less known. To enhance their color, these gemstones are subjected to numerous treatments. Depending on the heat treatment of pale yellow sapphire, the result may be intense yellow, yellow/golden, golden and deep orange-like yellow colors. Natural pale yellow sapphires are heated between 1600 to 1900 degrees centigrade to get better shades.

Purple Sapphires are often intense electric purple or plum color. Some have a gray or brown tinge. Exceptional one-carat purple sapphires from Africa and Burma range from $350 to $500 per carat. Larger purples can exceed $1200 per carat.

Color Change Sapphires are beautiful, with deep color saturation. Sapphire is one of the gemstones that can change from one color to another, depending on light source. Because of its atomic structure, these sapphires look blue in daylight and seem to go purple or violet under incandescent lights. The color change sapphire with a more dramatic change, is more in demand. The ideal sapphire with this quality has a 100% change with two attractive colors. One should not be able to see two colors under a single light source. More vivid the color change, more valuable is the sapphire.

Green Sapphires come from Australia and Thailand. Presence of black/gray secondary colors reduces its value. Pure green sapphires are also found in Africa and greenish blue sapphires come from Burma. Top quality green sapphires are sold for about $250 per carat.

White Sapphires were sold at a very low price of $10 per carat, until it was realized that the process of heating changed white sapphires to vibrant orange sapphires. Diffusion process changes these white gems to blue sapphires. With the increase in demand for these gems, the price of white sapphires now ranges from $100 to $300 per carat.

Star Sapphire displays a sharp six-rayed star in its center, commonly known as asterism. It appears in bright lighting and the quality depends on the sharpness of star, symmetry of the rays, and the body color. The American Museum of Natural History in New York City houses the largest cut star sapphire, the 543-carat "Star of India", and the "Midnight Star", a black star sapphire.

The single most important factor in determining the value of sapphire is its color. Even the most expensive sapphires have inclusions and are not clear like diamonds. Fine sapphires of good color and clarity are very rare. Sapphires with medium and dark medium tones are considered the best and the too dark and too light sapphires have considerably less worth. The most valuable of the blue sapphires is actually violet-ish blue.

Geological and Other Trivia

Sapphire deposits in Sri Lanka, Madagascar, Australia, Antarctica, Kenya and Tanzania are geologically related, as all were connected, billions of years ago, in a super continent called Pangaea. Sapphires, as well as other gemstones, from the same source were deposited throughout this super continent as alluvial gravels. Sri Lanka is known to be closest to this ancient geological source, as the largest sapphires, with better crystallization, are found there. Sapphires in Madagascar and Tanzania are smaller in size, due to the distance they had to travel.

Sri Lanka produces the largest and finest sapphires in the world and sapphires of almost every color is found there.

Certain people believe in the healing and astrological properties of sapphire. Sapphire is the birthstone of people born in September and a 5th and 45th anniversary gift. It is believed that dark blue sapphire will enhance one's full creative potential. The inspiration of light blue sapphire brings in new thoughts or ways of thinking. Green sapphire allows one's life to run smoothly and rightly. Orange sapphire does not allow you to deceive yourself at any level and helps you learn true knowledge. White sapphire is a personal stone and assists you in protecting yourself from needless sufferings. Yellow sapphire connects you with all of your inner knowledge.

 
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