Sapphires have been prized gemstones for centuries. Because of their brilliant hues, sapphires have been worn by royals and even included in crown jewels. For example, the imperial crown of Iran’s Pahlavi dynasty, which was the last dynasty to rule the country, includes a twenty carat sapphire. A particular sapphire brooch was prized in the Imperial Russian Court. The brooch consists of a sapphire over 260 carats in size which is surrounded by over 55 carats of diamonds.
While sapphires are beloved for their deep cerulean color, they are also often enjoyed for their color variations. A sapphire can be pink or white, instead of blue. Furthermore, there are some special sapphires that actually change color depending on their lighting. One of the most interesting sapphires, however, is the star sapphire.
A star sapphire is a lovely gem that exhibits a six pointed star because of the intersection of six thin intersecting inclusions. When the gem is lit from above, the inclusions become quite visible and the star shape appears. One of the most stunning star sapphires in the world is housed in the Smithsonian Institute. The Star of Bombay is a stunning oval star sapphire, 182 carats in size.
Just like any kind of gem, the quality of a star sapphire varies depending upon a number of factors. The size, color, and clarity of the stone are, of course, just as important as they are with other stones. The inclusions, which are normally made of the mineral rutile, also add or detract from the value of the stone. If the star is quite visible, then the star sapphire is likely to be quite valuable. Inclusions that are less visible, or murky, will not yield a highly valuable star sapphire.
It has become common practice to use heating techniques to deepen or alter the color of a gemstone. Such techniques are also sometimes used to increase the visibility of the inclusions within a star sapphire. In the age of synthetic gems and color-altering techniques, many jewelers and gem collectors have strong feelings about these practices. Some people feel that these techniques are wonderful because they can improve upon the beauty of stones, or make lovely stones without mining. Others, however, are against these practices and feel that naturally occurring brilliant stones are better than their counterparts. It is interesting to note, however, that even with star sapphires, it takes a strong microscope to tell whether or not the gem has been treated with heat.