One of the most amazing gemstones in the gem kingdom is sapphire, which is a mineral variety of corundum, an oxide of aluminum. The color of sapphire may vary from blue, yellow, green, purple or orange, depending upon the trace impurities found in nature.
This naturally occurring gemstone is remarkably hard and durable, measuring 9 on Mohs Scale of Hardness. Sapphires are basically ornamental gemstones and are available in different varieties, some of which are listed as follows:
Blue Sapphire Stone
Blue sapphire is the most beautiful variety in sapphire and comes in a variety of hues, varying from pale blue to vivid violet-blue color. For a blue sapphire to be categorized as true blue, the secondary hue must not account for more than 15% of its color.
A subclass of blue sapphires is cornflower blue sapphire, which represents an intense velvety blue color. Most of the blue sapphires have silk or inclusions present in natural form and these actually enhance the beauty as well as the value of the stones. Blue sapphire gemstone is known by the name of Neelam and is regarded as the gemstone of Saturn or Shani.
Yellow Sapphire Gemstone
Yellow sapphire, also known as Pukhraj is a gemstone related to Jupiter or Brihaspati and is worn to derive the benefits of this particular planet.
As the name suggests, the primary hue of the gemstone is yellow and its color ranges from greenish yellow to orange-yellow, with a vibrant canary yellow being the most desirable color. The presence of impurities of iron gives the stone its characteristic yellow color.
Pink Sapphire Gemstone
One of the most desirable colors in sapphire is pink. Pink sapphires occur naturally in different hues of pink, varying from pale pink color to a deep magenta color, which is attributed to the presence of trace impurities of chromium in the gemstones.
The value of the pink sapphire increases with the color saturation, which depends upon the amount of chromium present in it. The color of the pink sapphires is absolutely amazing, which makes them rare and in high demand.
Padparadscha Sapphire Gemstone
The rarest of the rare variety of sapphire is the Padparadscha sapphire, which occurs in tones of pink-orange, giving it a unique, alluring look.
The stones are totally natural and are seldom subjected to treatment. The fact is that they are little known to the common people, but are treasured by experts and collectors. The scintillating stones display an eye-catching color, which is often compared to that of a lotus.
Star Sapphire Gemstone
Another variety of sapphire is star sapphire, which exhibits a phenomenon called asterism, a star like a look in the stone.
It is caused by needle-like inclusions present within the gem structure and these inclusions intersect each other, forming a six-rayed star-like pattern when seen under a light source.
Color Changing Sapphire Gemstone
One of the rarest varieties among naturally occurring sapphires is that of color changing sapphires, which exhibit different colors when seen under different light sources.
The phenomenon is caused by the absorption of different wavelengths by the stone, which is the result of the presence of trace impurities of vanadium and chromium.
In addition to these varieties, sapphires are available in a colorless variety called the white sapphire or colorless sapphire. Some more color varieties of naturally occurring sapphire stones are green sapphires, orange sapphires, purple sapphires and black sapphires.