| Ruby sometimes displays a three-ray, six-point star. These star rubies are cut in a smooth domed cabochon cut to display the effect. The star is best visible when illuminated with a single light source: it moves across the stone as the light moves. This effect, called asterism, is caused by light reflecting off tiny needle like rutile (called "silk") arranged in three sets of parallel needles that intersect one another at 60o angles.
The value of star rubies and star sapphires are influenced by two things: 1) The intensity and attractiveness of the body color, and 2) The strength and
sharpness of the star. All six legs should be straight and equally prominent. Star rubies rarely have the combination of a fine translucent or transparent color and a sharp prominent star, but when offered, these gems are valuable and expensive. Star Ruby is somewhat heat sensitive, a jeweler's torch could alter the color or star, it may be prudent to ask a Jeweler to remove the stone before applying his torch. There are not very many chemicals that could attack this gem, but if boiled in a diamond cleaning kit the stone can lose it's polish, also Jewelers pickling solutions containing boron will etch the surface. Our source for fine Star Sapphire is Sri Lanka (formerly Ceylon), known for producing a fine variety of Sapphire. We occasionally come across a Burma Star, and these are even more of a rarity thus commanding an extremely high premium. Other sources for Star Rubies are Australia, Thailand,
Vietnam, Kampuchea, and India. Fine Burma and Ceylon Top Gem Quality Star Rubies are very highly valued Collectors Gemstones.
TREATMENTS - Genuine Star Ruby is not typically treated with 'heat' or any other treatment to enhance the color or alter the clarity. If a Star Ruby were to be heated the person doing the heating seriously risks dissolving the rutile needles that cause the asterism to form a star, thus rendering it a plain Cabochon Ruby worth far less than it is as a natural non-heated non-treated Top Quality Star Ruby.
The following links are to reputable Gem Laboratories and Appraisers :
CARE - It is risky to clean Star Ruby in an UltraSonic Cleaner, and risky to use a steamer. We recommend Ionic Cleaners and/or warm, soapy water and a soft brush as the most trustworthy way to clean Star Ruby jewelry.
NOTE - Most commonly you will see that synthetics jump out as way too perfect looking, ie: a perfect star, a super clean stone, and great color. If you own one and aren't sure if it's genuine... Here's a few quick ways you might be able to tell the difference... First thing to look at is the bottom, if there is an "L" stamped in the stone, it's a Lindy Star and synthetic... if it does not have an "L", it passed that test. Now look for imperfections within the stone, and look for unevenness on the bottom, and look for stripes or lines of color that shows through the top. Almost all natural Star Rubies will have one or more of these natural imperfections. Next look at the star using a flashlight... almost all natural stars won't have a "perfect" star. The natural stars will most likely have 1 or more of the 6 legs not exactly the same length, or maybe not all 6 are perfectly straight. Next go ahead and move the flashlight around in a circle, if the star stays stationary it is definitely synthetic. The star on a genuine star will travel around and follow the light source. When you look at the bottom of the gem, note that synthetics are always flat on the bottom, and usually have a very low dome, whereas the natural star typically will have an uneven bottom that may even have chunks of stone that appear to be missing, or dark spots on the lower portion of the gem. If it passed all these tests you may have a genuine Star Ruby, but don't get super excited yet, these are just simple things you can do to rule out the majority of synthetics, the only way to be sure is to send the stone to a certified reputable Gemologist and ask for a Gem Identification Report.