Sapphire
Consumer Information
What color is it?: Well, as you see above it can be a lot of colors. Sapphires actually occur in virtually every color of the rainbow. Above you see a blue and a green. And below you will find some orange and purple. Name a color and you will find a sapphire very close. Except for the pure red stones. These are rubies. But anything with a strong purple overtone or definite pink color will be properly called a sapphire.
What is the story behind this gemstone?: One of the most beautiful and historic gemstones in the world. Sapphires speak for themselves I believe.
Can I wear it everyday?: Absolutely. Second only to diamond in hardness. And very tough to break (although it can be done).
Is it expensive?: Yes they can be. And please read this: Most sapphires are heat treated to enhance their color. If it were not for heat treatment (see Gemstone Treatments) we would not have many sapphires. But a true natural, unheated sapphire of fine blue color will be very expensive. Sometimes tens of thousands of dollars. While the heated stones can be very beautiful and cost only hundreds of dollars. You choose which you would like to have. But be prepared. If you are offered a less expensive sapphire that is a beautiful color, it is more than likely heated. If you are told otherwise be very cautious.
Is it a birthstone?: Yes, September. (blue)
What
do I need to know before going shopping?: Keep some common sense about you. Sapphires
of 5.00 carats or more are available in department and discount
stores for only a couple of hundred dollars. But they are so dark
they look black. Like black onyx. It may sound great that you
are getting a huge sapphire at such a deal, but
stand back and look at it....its ugly. Too dark to show any color.
Sapphires are supposed to show beautiful colors. And you get what
you pay for. Look for some unusual colors in sapphires. They can
be very, very unique. But forget the big cheap dark, dark sapphires
from the discount stores. After all, who are you going to impress
at the party with a big ugly black rock on your hand?
General Information
Two examples of bipyramidal crystal growth of sapphire. Twinned green bipyramids (right) single blue bipyramids (left)
Source: World Wide but mostly from the Far East countries like Sri Lanka, Thailand, and Burma
Chemical: Al2O3 aluminum oxide
Formation: Mainly in igneous rocks
Crystal System: Hexagonal but generally occurs in the twinned bipyramidal green sapphire crystals as shown above, and in Crystal Systems sections elsewhere in this site.
Unusual
Properties: Many. Including
color change, chatoyancy and star sapphire as shown here with
a black star sapphire.
Gemological Information
Orange Sapphires shown above
RI: 1.762 - 1.770
Birefringence: .008
Optic Character: U-
Specific Gravity: 4.00
Hardness: 9 (second only to diamond)
Transparency: TP- Opaque
Special Identifying Properties and Tests:Spectroscope can separate some untreated sapphires from heat treated naturals and some synthetics by presence of iron lines at 4400. Curved striations and gas bubbles visible in flame fusion synthetics.
Synthetics: Yes, since 1890.
Imitations: Many and varied.