Believe it or not, one scene in an 1829 bestseller by Sir Walter Scott, Anne of Geierstein, destroyed the European opal market for nearly 50 years. One of the book’s characters, accused of being a demon, dies shortly after her mysterious fiery opal loses all color when touched accidentally by a drop of holy water. Was the poor woman really a demon and her opal some kind of infernal talisman? Or was she simply a victim of her—and, by implication, all opal’s fragility? Readers took no chances and immediately stopped buying the gem. Within a matter of months, the market had crashed and opal prices were down at least 50%.
It took a remarkable find of black opal at Lightning Ridge in New South Wales, Australia, in 1877, to revive the market for this gem. Australia’s spectacular new opals took the world by storm. Indeed, there have been almost no opals found in the last 50 years to match what came from Lightning Ridge in its late 19th and early 20th century heyday.
No wonder dealers sometimes liken Lightning Ridge’s significance to that of Kashmir for sapphire, a Himalayan source discovered around the same time that set the standard for sapphire in the same way Lightning Ridge did for opal.
To get some idea of the standard Lightning Ridge set, pause now and study the picture on the facing page. The gem you see there is a magnificent example of Lightning Ridge opal, one that came from a dealer’s private collection and is assumed to be turn-of-the-century. Stones far less prettier fetch $4,000 to $5,000 per carat today in mere 5- to 6-carat sizes—if one can find them.
It won’t be easy locating such stones in America or, for that matter, Europe. You’ll have a far better chance in Asia. Indeed, if any gem can be called a one-market stone, black opal comes the closest to it. That market is Japan.
“Japan consumes at least 50%, and perhaps as much as 70%, of the world’s black opal production,” says opal dealer S. David Brookes, Darneotown, Md. “Knowing that fine black opal can bring huge sums in Japan, Australian dealers pay more for stones on the opal fields than they could ever hope to sell for here in the United States.”
Because the Japanese are willing to pay so much, especially for 2- to 4-carat stones, U.S. opal specialists like Brookes and Gerry Manning, Manning Opal and Gem, New York, devote less than 10% of their inventories to black opal. Instead, they stock white opal. “America is to white opal what Japan is to black,” Manning says. “Only here the emphasis is on inexpensive goods.”
Lightning Strikes Once
Black opal is far rarer than white opal. In fact, there are only two actively producing black opal localities in the world, both in Australia. Lightning Ridge, is said to produce true black opal, and the other, Mintabe, is known more for gray to grayish-black material. Some purists even protest calling Mintabe stones black opal. They do so on both geological and aesthetic grounds.
Traditionally, black opal was considered a variety of opal found in rock formations called nodules (or “nobbies” in the trade) as opposed to white opal which is found in seams. But when Mintabe, whose opal is found in seams, was discovered, this geology-based distinction began to blur. By allowing this dark gray opal to be considered black opal, the world supply of black opal rose considerably. But because it was gray not black, it was also much more affordable.
Even so, when Lightning Ridge and Mintabe opal are taken together, there is still far less black than white opal. Given its relative scarcity, black opal has never lent itself to mass cutting in standard sizes such as you find for white opal. The lack of calibrated black opal has prevented its popularization in large-volume U.S. jewelry manufacture. So black opal remains primarily a special-order stone in this country. But the few who buy it here generally look for the same things the Japanese do: base color, hue mixture and color pattern.
Basics of Opal Beauty
First comes base color. The darker the base—or what dealers call “potch”—of an opal, the more pronounced and vivid its color. “That’s because an opal’s beauty is the product of the contrast between its color play and its background,” explains respected New York lapidary Reggie Miller, Reginald C. Miller Inc.
As for ideal color in black opal, Miller looks for the predominance of red and then orange. “Stone’s that appear all or almost all red are the most coveted,” he says. “Increasing amounts of blue and green will reduce their value.” But specific color isn’t all that Miller wants in a fine black opal. The pattern that they appear in is equally important to him. For years, the most sought-after pattern was what is called the “harlequin”: well-defined squares, rectangles, triangles or diamonds of color in both symmetrical and non-symmetrical designs.
“Today, unfortunately, the harlequin pattern is encountered only in older pieces,” Brookes says. “No new stones with this pattern have been mined in years.” Instead, connoisseurs content themselves with stones that exhibit broad well-defined flashes of color (called “rolling flash”) that change kaleidoscopically as stones are turned in the hand. Even these designs are not very plentiful. Most black opals that jewelers see contain less prized but often beautiful patterns comprised of pointillistic dots. As these dots get smaller and less vivid, they come to resemble what the trade calls “pinfire.” Such black opals are the most commonly found and least expensive.
Fears of Cracking
Because opal is gelled silica, containing as much as 20% water, some of it tends to dry out and crack after being mined. This can happen almost immediately upon being taken from the ground or years later. This is called “crazing” and wipes out the value of a stone. However, it is supposed that black opal has a lower water content than white and therefore is more stable. But opal dealers we talked to won’t say for sure.
Equally bad news is the fact that certain measures—sealing stones with oil or leaving them in jars of water—thought to prevent crazing do not work. “The only thing you can do is to buy from a supplier who lives with his opal for some time before he sells it,” Manning says. “In that way, he’ll weed out most of the bad stones for you.”
One last tip from Manning, regarding cracked opal: “Handle it sensibly. The last thing you want to do is to display it continuously under bright lights.”
Please note: this profile was originally published in 1988 in Modern Jeweler’s ‘Gem Profiles: The First 60’, written by David Federman with photographs by Tino Hammid.
The Australian black opal shown in the header image is courtesy of Leo Boyajian, Naples, Fla.