Sapphire - gem of the corundum group

There are two color varieties of corundum. We distinguish the red ruby ​​and all other colors comprehensive sapphire. All common corundum, which will have no quality jewelry used for jewelry purposes and not used as an abrasive. Everyone is familiar with sandpaper, is used for fine-grained corundum.

THE SAPPHIRE

The term sapphire (gr.blue) was formerly used for different stones. In part to the Middle Ages was understood to be sapphire today's most lapis lazuli. By 1800 it was recognized that constitute ruby ​​and sapphire gem qualities of corundum.

Padparadscha Sapphire

Today, sapphires which are not identified by a qualified blue word, such as yellow or green sapphire.
The name sapphire is always based only on the blue variant. Colorless Sapihre, which also serve as a diamond substitute, is known as Leukosaphir (large white). The term "Padparadscha means reddish to
orange and yellow sapphires. Since bright red, pink or purple corundum in the group of jewels would be classified as inferior, they are counted as sapphires, because here they have an independent value.

Also sapphires are made ​​of alumina. The different colors depend on color-producing substances on, the blue sapphire iron, titanium, vanadium in purple, yellow and green colors by trivalent iron, pink colors with chrome, orange by iron and vanadium. It is most appreciated is the plain cornflower blue .

Star Sapphire

As with Rubin can by firing at about 1700-1800 degrees Celsius bright blue, consistent color from dull, nondescript color sapphires generated. The hardness of sapphires is the same as that of the ruby. There are also, like the ruby deposits of finely aligned needles (even fine cracks) the so-called cat's eye effect or a six-pointed star ( star sapphire ).

Large sapphires are rare. You get some of his own name as well as famous diamonds, such as "Star of India" or "Midnight Star"

Deposits

Yellow Sapphires

Rocks of the sapphires are limestone, marble, basalt or pegmatites. The extraction takes place, as with the ruby, mainly on alluvial deposits or Verwitterngslagerstätten. The gem-bearing layers can be achieved by dug holes or worn suspension. The separation of sand, clay or gravel is washed through, since sapphire has a high density (3.95 to 4.03) has. Ultimately, the selection is carried by hand.

Sapphires are much more common than rubies, as well as coloring substances are more common.

Economically important sites are located in Australia, Myanmar, Thailand and Sri Lanka.

Two Cabochons

In Australia they are found in Queensland, where the quality is rather modest. In artificial light, the color ink-stones, blue-green to almost black. Bright stones have a greenish tinge. There are also black star sapphires. Since 1918, there are discoveries in New South Wales with good blue quality.

In Myanmar you will find just as with large deposits in Mogok ruby. This star sapphire was 1966 with 63 000 ct found. This corresponds to a weight of 12.6 kg.

In Sri Lanka, the deposits are located in the southwest of the island. Here are encouraged sapphires are purple with a shade of light blue. There are also yellow and orange varieties (Padparadscha), and green, pink, brown and almost colorless stones, moreover, star sapphires and sapphire cat's eyes.

Gemstone mine in Sri Lanka

In Thailand, the deposits are located southeast and northwest of Bangkok. Good qualities of different colors, and star sapphires. The blue sapphires have a deep color but tend to blue green.

It was the best qualities in Indian Kashmir cornflower blue in color. Today as Kashmir sapphire stones are usually offered from Myamar.

There are other smaller reserves.

Even when there are imitations of sapphire glass as cobalt or duplicates.

Beginning of the 20th century, synthetic sapphires with properties of the natural grown very same. Since 1947, there are synthetic star sapphires of gem quality.