Rare, beautiful opals are the 'queen of gems'

Fabian H. Chandra, Gemologist, Jakarta

Few know that the Banten area, in the west part of Java, is famous for its opal, which is believed by the Javanese to be a lucky stone. Gemstone lovers call it the "queen of gems."

Opals, also dubbed an "impressive dream stone", are ranked the sixth-most precious gemstone after diamonds, rubies, emeralds, sapphires and the Chrysoberyl group, due to their rarity and beauty.

The word "opal" derives from the Sanskrit word, upala, meaning precious stone.

Opals were formed by the construction of tiny silica spheres, and light diffracted through this structure causes interference and iridescence. Interference is like the play of color found on a thin film of oil on water, and is iridescent.

From many varieties of opal black ones are ranked the most valuable and most expensive internationally. They are very precious, with dark gray, dark blue, dark green and gray-black basic colors and a play of color.

The most beautiful black opal, sometimes called deep black, can be more expensive than D (colorless) flawless diamonds. It can drive someone crazy, as it is incomparably beautiful.

Most black opals are found in Indonesia, especially Banten, but are not bright and are unstable. They also become crazed if dried, due to a high water content within the silica spheres when formed or exposure to a sudden temperature shock and humidity change.

That means the price of black opals is lower than that of other varieties, especially white ones.

Some of these varieties are also unstable but unlike crazing in black varieties, white opals develop a partially white colored spot inside if dried, caused by porosity, which reduces their price. Most of these gems return to their original beautiful color after soaking in water.

People say Australian opals sold in some jewelry stores here come from Banten, as both are of equal quality. In fact, some Banten opals are exported to Australia and the United States under the label, "Australian opal from Coober Pedy or Lightning Ridge".

Another variety is a type of black, dark brown or brown-to- white porous opal known as a Chameleon opal. They are transparent if soaked in water but lose their play of color significantly. When dried, they retain their maximum color play, but are less transparent.

The difference between these two opals can be easily recognized. Put the stone, which has been thoroughly dried, on one's moistened lip. If the stone sticks to the lip it is definitely a Chameleon.

The determining factors for opal prices include the tones of the opal's body color, type and intensity of play of color, pattern, shape of cut and, of course, weight in carats.

The red type is most prized, followed by orange, yellow, green and finally, blue.

Intensity of play of color has been divided by one expert into five grades, with brilliant as the most intense and most bright followed by very bright, then bright, dull and faint.

The best opal can have an unbelievable play of color that is unrivaled by any other gem. It can be extremely bright. Only the color of certain tropical butterflies is comparable.

Harlequin is the angular patches pattern. It is the rarest and commands the highest price.

Banten natives call this pattern tikar ajaib (magical mat).

The low-domed oval cabochon is the most preferred shape of cut.

Most Indonesian opals are cut this way due to limited knowledge on how to cut natural free forms and how to cut opals properly, which has often resulted in some extremely beautiful opals having a lower quality and value.

The weight is directly related to size and therefore is very important.

Most diamond-lovers adore the gems mostly for their price and investment value rather than their intrinsic beauty. Their lack of appreciation of opals is understandable, as opals are not advertised heavily by syndicates, as De Beers does for diamonds.

But opal lovers have a true love of this gemstone. If someone falls in love with the "queen of gems", particularly a top quality masterpiece, the person will not be satisfied with anything else.

Why?

Because opals are so beautiful. The intensity of its play of color is very brilliant.

To describe the beauty of opal briefly: "Even to the last breath of your life, you will never voluntarily be willing to part with this beautiful stone and once you have a top quality opal you will pray to God for permission to it carry with you, this most beautiful gemstone of yours, to heaven."