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Blue Star Sapphire Information

Blue Star Sapphire Information

Some rare natural sapphires exhibit a star-like phenomenon known as asterism. These gems contain intersecting needle-like inclusions (often the mineral rutile, a mineral composed primarily of titanium dioxide) that cause the appearance of a six-rayed star when viewed with a single overhead light source. To cause a star, the rutile needles need to form in parallel and tightly packed groups. The reflection off of each group of crystals forms a straight line which appears to float on the surface of the stone. There are always three groups of crystals which intersect at 60 degree angles from each other. The three lines formed connect in the center to form the appearance of a 6 ray star.

The presence of a star is one of the more remarkable phenomena encountered in the world of colored gemstones. This optical phenomenon is quite rare, being only found in a tiny percentage of the sapphires mined around the world. Star sapphires can occur in any color, but the most common colors are blue, black and pink. Since red corundum is referred to as ruby rather than sapphire, a red star would be be called a star ruby.

When looking to buy either a Blue Star Sapphire or a Pink Star Sapphire, remember that the value depends not only on the carat weight of the stone but also the body color, visibility and intensity of the asterism.

The prices and value of star sapphire vary depending the size and quality of the gemstone. The saturation and consistency of the body color are quite important, as are the visibility and distinctness of the star. However, there is often a tradeoff between these, since the more rutile in the gem, the weaker the body color and the stronger the star. A good balance of body color and a clear star is preferred. Most star sapphires are opaque, but specimens with some degree of translucency are more highly valued by collectors.
Why Buy Loose Gemstones Instead of Pre-Set Jewelry? 

There are many reasons, but basically it comes down to two factors: value and choice.

When buying a loose gemstone instead of a pre-set stone, you can be sure you are getting the best value for your money.  Loose gemstones are less expensive, a better value, and you can really see what you are paying for.  The most important part of getting the right price and finding the best value is to first see what you're getting.  A jewelry setting will hide the inclusions inside a gem, and can deepen or brighten its color.  With a loose stone you can much more easily inspect the gem and see it for what it really is.  In this way you can get a better idea of its true worth and be sure you are paying a fair price.

The second advantage of buying a loose gemstone is choice.  You are free to pick the exact color, cut, shape and variety of the stone for the setting of your dreams, be it yellow gold, white gold, platinum or silver; prong set or bezel set.  You can experience the joy of creating your very own, one-of-a-kind jewelry design. Choose from a variety of jewelry settings and styles to create a completely original presentation that will perfectly suit your individual gemstone and will be as unique as you are!

     Blue Star Sapphire Platinum Ring


Origin Madagascar, Thailand, Sri Lanka, Ceylon, Burma, Burmese, Australia, India, Kenya, Tanzania, U.S.A., China
Color All shades of blue and pink
Refractive Index 1.759-1.778
Chemical Composition  AL2 O3
Hardness 9
Density 4
Crystal Structure Trigonal
Zodiac Sign Libra
Planet Venus
Month September
Anniversary 5th and 45th
Star sapphire's fascinating asterism is just one reason for this gemstone's popularity. As with all sapphire, they are also very durable, having a hardness of 9 on the Mohs scale. Sapphire has a specific gravity of 4.00, a refractive index of 1.76 - 1.78, and birefringence of 0.008.  The refractive index (RI), measured using a refractometer, is an indication of the amount light rays are bent by a mineral. Birefringence is the difference between the minimum and maximum RI. When birefringence is high, light rays reflect off different parts of the back of a stone causing an apparent doubling of the back facets when viewed through the front facet.
Most gems have a crystalline structure. Crystals have planes of symmetry and are divided into seven symmetry systems. The number of axes, their length, and their angle to each other determine the system to which a crystal belongs.  Blue Star Sapphire and Pink Star Sapphire are both classified as having a trigonal crystalline structure because they have three planes of symmetry and four axes. Three axes are at 60 degrees to each other in the same plane. The fourth axis is perpendicular and unequal in length to the other three. The form of a sapphire's crystals depends on the variety and locality. Sapphires may have an uneven or a conchoidal fracture but no real cleavage. The amount of light reflected at the surface of a gemstone is its luster and blue sapphires have a glassy (vitreous) luster as opposed to the waxy, greasy, or resinous luster of other stones.


Color is the single most important factor in determining the value of a sapphire. But in star sapphires it is a combination of the body color and the distinctness of the star. Since rutile inclusions which cause the asterism effect also tend to weaken the body color, there is usually a tradeoff between body color and asterism.

The name sapphire comes from the Greek word "sapphirus", meaning "blue".  However, sapphire gemstones come in many colors including pink, yellow, orange, green, black, color-change, purple, violet, light blue, and the rare orange-pink Padparadscha sapphire gems. Padparadscha comes from the Sinahalese word meaning "lotus color". Sapphires other than blue, pink, yellow, green and orange sapphire are usually called "natural fancy-color sapphire". Red hues result from traces of chromium. The greater the concentration of oxides the deeper the color.



Ovals, rounds, cushions and emeralds are the most common cuts for sapphire, due to the typical shape of sapphire rough. Other popular sapphire shapes include pears, briolettes, hearts and  marquises. Star sapphire are always cut as cabochons in order to develop and properly display the star effect.  Fibers or fibrous cavities within some gems reflect the light which causes a star to appear within the stone. A six-ray star sapphire has three sets of parallel fibers. Skilled cutters can sometimes create a 12-ray star sapphire but they are rare.


High quality star sapphires are not treated in any way. Some lower quality material is diffusion treated with rutile to improve the star. Recently we have seen some low quality star sapphires and star rubies which have been fracture-filled with lead-glass.

Sosnagems fully discloses any and all treatments to our gemstones.


Throughout history the two sources producing the best quality star sapphires are Burma and Sri Lanka. Madagascar is a new, but increasingly important, source.
Sri Lanka is the source of the biggest fine quality blue star sapphires in the world. Several famous museums have giant star sapphires from Ceylon that exceed 100 carats in weight. These include the Star of Artaban, a 316 carat blue star in the Smithsonian Institute, and the Star of India, a 563 carat fine blue star that is on display in the American Museum of Natural History. An unnamed 393 carat blue star owned by the State Gem Corporation of Sri Lanka is believed by many to be the finest blue star sapphire of its size in the world.
Big stars from Burma are considerably more scarce than those from Ceylon. There is only one found in any of the major museums of the world. It is the 330 carat Star of Asia, a 330 carat blue-violet colored gem found in the Smithsonian Institute. While Burma does not produce so many stars of exceptional size, it is generally considered to be the source of the finest color.
Sri Lanka
 Ceylon Sapphire Gem Mining                                                                                         Ceylon Sapphire
Mining on the island of Sri Lanka goes back at least 2000 years. This island has its own heritage in the mining arena. The island is called Gem Island or "Ratna Dweepa" because of the large variety of gems found here. You will find everything from peridot to moonstones to garnets and topaz. Today Sri Lanka is best recognized for it's the sapphires called the Ceylon Blue, and the sapphire called Padparadscha which has a beautiful and unique orange pink pastel soft color, very similar to the Lotus flower found on this island. The traditional Ceylon mines are near Ratnapura which is located southeast of Colombo about 100kms away.
Sri Lanka is still one of the world’s largest sources of fine quality blue sapphire. It is a place where one can regularly find excellent gems over the 100 carat mark. Many of the famous large sapphires in museums around the world came from this gemstone rich tropical island. Sri Lanka is also a very well known source for fine quality star sapphires.
The classic “cornflower blue” is what Sri Lanka is best known for. The finest of the sapphires from Ceylon are a very even and intense pure blue color, with a high degree of saturation. This bright and medium toned shade of blue is highly prized around the world, and is considered to be far superior to the often overly dark and inky colors commonly found in Australia and Thailand.
The area know as Ratnapura sits right in the middle of the gem producing area of Sri Lanka. Surrounding this town one can see hundreds of small to large hand dug pits where the gemming (Sri Lankan term for gem mining) is going on. The government has put a total ban on mechanized mining, thereby assuring a tight supply, stable prices, and a source of income for many future generations of poor indigenous laborers.
Burma, which is today called Myanmar, has several important locations that produce sapphire. The most famous is the Mogok gem tract which has a rich history of production dating back several hundred years. Sapphires from Burma were not recognized for their superior quality until the 1950's, after which their value and demand has risen dramatically. 
But what exactly is it that makes blue sapphires from Burma so superior to gems from any other location? In visual terms it is what is known as color saturation. Burmese sapphires possess some of the very highest concentration of blue color possible. The only way to properly understand this is to see the very best of Burmese sapphires side by side with the best from any other source in the world.


The myths, legends, beliefs, superstitions, traditions and symbolism associated with sapphire have been numerous...

Legend has it that the first person to wear Sapphire was Prometheus, the rival of Zeus, who took the gemstone from Cacaus, where he also stole fire from heaven for man.

Known as the "Gem of Heaven", the ancient Persians believed Sapphires were a chip from the pedestal that supported the earth, and that its reflections gave the sky its colors.

Tradition holds that Moses was given the Ten Commandments on tablets of sapphire, making it the most sacred gemstone. Because blue sapphires represent divine favor, they were the gemstone of choice for kings and high priests. The British Crown Jewels are full of large blue sapphires, the symbol of pure and wise rulers.

The guardians of innocence, Sapphires symbolize truth, sincerity and faithfulness, and are thought to bring peace, joy and wisdom to their owners. In ancient times it was believed that when the wearer of a Sapphire faced challenging obstacles, the gem's power enabled them to find the correct solution.

In India it was believed that a Sapphire immersed in water formed an elixir that could cure the bite of scorpions and snakes. Alternatively, if it were worn as a talisman pendant, it would protect the wearer against evil spirits.

The following legend is Burmese in origin and highlights Sapphires‘ connection with faithfulness: “Eons ago Tsun-Kyan-Kse, a golden haired goddess with Sapphire blue eyes, presided lovingly over the temple of Lao-Tsun. Everyday, the temple‘s chief monk Mun-Ha, meditated before the golden goddess accompanied by his devoted companion, a green-eyed cat named Sinh. One day the temple was besieged by a group of terrible outlaws. When they threw Mun-Ha to the floor, Sinh leapt fiercely at the bandits, jumping up on his master‘s chest to protect him. The wrong doers fled screaming in fear, never to return and in gratitude for his courage, the golden goddess awarded Sinh with her Sapphire blue eyes. To this day, Sinh‘s ancestors guard over the temple.” The temple still stands and is populated by Siamese cat‘s with striking blue eyes (typically this breed has green eyes).

For hundreds of years Blue Sapphires were the popular choice for engagement and wedding rings.