STAR SAPPHIRE |
|
STAR SAPPHIRE |
|
Follow us
|
|
|
Star Sapphire Facts Birthstone Info
|
|
 |
||
|
|
||
email
 Contact
|
||
| 1-805-735-7103
Hours : Mon-Fri 10am-5pm Pacific Time 24 hours Voice Mail |
||
Star Sapphire Information |
|
THE ALTERNATE BIRTHSTONE for AUGUST |
|
MOH's scale of hardness : 9 |
Toughness : Excellent |
Refractive Index : 1.762-1.770 (+.009, -.005) |
Specific Gravity : 4.00 (+.10,-.05) |
| Sapphire sometimes displays a three-ray, six-point star. These star sapphires 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. Star Sapphire is usually found in Blue colors, but there are also various shades of brown and green that are called Black Star Sapphire. Orange and Yellow Star Sapphires are almost unknown, and very rare. Color Changing Star Sapphires are even more of a rarity. The value of star sapphires are influenced by at least these two things: 1) the intensity and attractiveness of the body color, and 2) the strength and sharpness of the star. Of course all six legs should be fairly straight and equally prominent. Star sapphires rarely have the combination of a fine translucent or transparent color and a sharp prominent star, but when offered, these gems are highly valued and the most expensive. 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 Sapphires are Australia, Thailand, Vietnam, Kampuchea, and India. Fine Burma and Ceylon Star Sapphires are highly valued Collectors Gemstones. TREATMENTS - Genuine Star Sapphire is not typically treated with 'heat' or any other treatment to enhance the color or alter the clarity. If a Star Sapphire 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 Sapphire. |
|
