Ask a gem collector which variety of opal is the most prized in the world and chances are pretty good you’ll get the right answer: Australian black opal. But don’t ask which kind is the next best. The answers you’ll usually hear—Australian semi-black or boulder opal—are wrong.
Collectors can be excused for not knowing the runner up in value terms to black opal. Unless they’re connoisseurs, they may never have heard of the world’s second most valued opal. Called black crystal opal, it’s also from Australia. But unlike, say, boulder opal, which is a distinct variety of this gem, black crystal opal is more akin to a sub-species. Indeed, most opal guidebooks classify black crystal opal between well-known black and semi-black when it comes to both value and regard. So how come few people know about it when it’s so highly esteemed?
That’s a tricky question, one whose answer sounds like a Zen riddle. Collectors do know about crystal opal, only they don’t know that they know.
Unless explained by an expert, black crystal opal is very likely to be mistaken for black, semi-black or even gray opal. That’s because most people who have seen black crystal opal probably weren’t told what they were looking at.
The same goes for light crystal opal—even more so. Since crystal opal occurs in both light and dark forms, and since light (or white) opal is a jewelry store staple, the odds are great that jewelers may have sold light crystal opal without labelling it as such.
But now that black crystal beauties from Lightning Ridge, Australia’s most famous opal mining area, are more available, consumers should take note of this stunning opal.
Great Balls of Fire
The name opal is a shortened version of opalus, a Roman coinage that sums up this gem’s chief aesthetic attribute: color play. Perhaps the best description of opal ever penned is found in Pliny the Elder’s treatise from 79 AD, Natural History, which devotes a volume to gems: “For in them you shall see the living fire of ruby, the glorious purple of amethyst, the sea-green of the emerald, all glittering together in an incredible mixture of light.”
