![linde star sapphire linde star sapphire](https://i.ebayimg.com/images/g/bekAAOSwc2Zd5Tsv/s-l300.jpg)
The Linde company later became a division of Union Carbide. Linde star sapphire ("Linde stars") are synthetic ~ that were first made by the Linde Air Products Company in 1947 (they also developed star rubies that year). ~ are rare and most of these gemstones are sold untreated. This phenomenon can be seen in almost all types. This is the result of small needle-like rutile inclusions. When viewed from above, ~ will exhibit a six-rayed star floating across the surface.
![linde star sapphire linde star sapphire](https://images.aspireauctions.com/auctions/2006NOV/large/15092-01.jpg)
Weighing a huge 563 carats, it is a stunning gemstone and on a recent visit to the Natural History Museum in New York, I was amazed at how long I had to queue just to walk past this star attraction. Possibly the most famous of all ~ is the Star of India. Sapphires, with a hardness of 9, are second only to diamonds in durability. Currently sapphire is the world's most popular colored gemstone with the US leading in purchases. It is extremely rare to find a star-sapphire with a sharp star and a bright blue body color.Īlthough commonly thought of as blue corundum, sapphire occurs in a wide color range, as well as in phenomenal form, as ~. ~ are judged by the sharpness of the star, the evenness of the rays or "legs" of the star, and the body color of the sapphire. ~, which are becoming more rare, are very popular for men's rings. Care should be taken when identifying all forms of star corundum, as synthetic stars are very inexpensive to produce and are common. These six-rayed blue stars are very attractive and are much more valuable than the black variety. This is really too much to ask from a natural gem.īlue sapphires are found in the form of ~. Of course the synthetic star's legs were perfect, and consumers began demanding the same from the natural gems. The inclusion is often the mineral rutile, a mineral composed primarily of titanium dioxide.Īlso, in the 1940s, Linde, a division of Union Carbide, began manufacturing synthetic ~. ~ contain intersecting needle-like inclusions following the underlying crystal structure that causes the appearance of a six-rayed "star"- shaped pattern when viewed with a single overhead light source. Summer 1947, Distinction Between Corundum and Garnet, p. Winter 1944, American Synthetics Available from Linde, p. 98, 1p.įall 1939, Lined, Foil- Backed Corundum Produces Stars and Cat's-Eyes, p. Summer 1937, New black Star Sapphires Found, p. it is caused by inclusions of tiny, parallel, rutile needles and may result in four, six or even twelve rayed stars. Related categories ~, Mineral Specimens and Rough Mineral SlabsĪsterism a luminous star like effect exhibited in some gemstones like ~, garnets and rubies.
![linde star sapphire linde star sapphire](https://i.ebayimg.com/images/g/yKUAAOSwv0tVW82P/s-l400.jpg)
But the best quality ~ are available in Sri Lanka. Weak and less well formed stars along with weaker body color is typical of natural stones.įiner qualities ~ are found in Myanmar (Burma), Thailand, India, Sri Lanka, Tanzania, Afghanistan, Brazil, Cambodia, Malagasy Republic, Malawi, Pakistan, Rhodesia of Zimbabwe and Montana and North Carolina of US. ~ will have silk or sets of parallel rutile needles that produce a 6-ray star, hexagonal growth lines, color zoning and mineral inclusions. If this rutile is sufficiently abundant and precisely arranged, proper cabochon cutting can create six-rayed ~. Sapphires can display asterism or the "star effect" due to rutile inclusions in their hexagonal crystal matrix. They come in many colours, the most common being grey or blue. ~ are usually translucent or opaque, and are commonly found in Sri Lanka, the United States and Australia. This effect displays a thin band of light down the center of the stone and is known as chatoyancy. Rarely, when sapphires are cut en cabochon, they can demonstrate a cat's eye effect. ~ usually have six ray stars, but twelve ray stars are also known. ~ are created when Corundum is intergrown with fibrous inclusions of Rutile, called " silk," that reflects light in stones cut en cabochon as a six-rayed, sometimes twelve-rayed star that appears to glide across the face of the gem as it is moved. These can be quite valuable if the star is centered and well-defined. Star Sapphires: Natural sapphires that exhibit an asterism. Ruby guide Emerald guide Tanzanite guideSemi preciousPearl educationGlossary Sapphire colorSapphire claritySapphire cut qualitySapphire carat weightStar SapphiresSapphire checklistBuying Sapphires abroad