Corundum is hardly a word that flows trippingly off the tongue in any conversation about fine gems. But corundum, a crystal form of aluminium oxide, abounds in jewelry. Perhaps you know the fine gem versions better by their more glamorous monikers: sapphire and ruby, which is how all red corundum is referred to.
After diamonds, sapphires and rubies are the most prized gems, and no wonder. Exceptional specimens of these gems, mostly from Myanmar, Kashmir or Sri Lanka, are rare and very expensive—often higher than diamonds.
But there’s more to the sapphire story than the fine blues, pinks and yellows that are carefully faceted by expert gem cutters. Like diamonds, there’s even a vast range of colors available in sapphires, or corundum: blue, red, violet, pink, green, orange, gray, white and black—there are also multicolored ones.
That treasure trove of corundum is being dug up and expanded upon these days in fine jewelry—in some unexpected ways. Besides using transparent, faceted versions found in sapphires, designers have expanded their gemstone palettes with a variation of corundum hues, many of them bearing little resemblance to the traditional, faceted stones usually associated with sapphires.
These corundum pieces more closely resemble naturally formed crystals before they are cut. Yet they have the same properties as sapphires—they’re the hardest mineral after diamonds—but have a more earthy appeal. It’s the same kind of back-to-nature bent that has made raw natural diamonds and slices of diamond crystal so popular.
Although some of the colors resemble their fancier sapphire cousins, these corundum pieces are often translucent, a bit milky or in some cases, nearly opaque. Predominant colors include deep, almost lapis lazuli-like blues (Italian designer Federica Rettore describes them as “velvet blue”), a pinkish, mauve color, and golden honey-colored hues. Often, even in sliced versions, this corundrum is given subtle rose-cut faceting on their surfaces, which take advantage of the gems’ natural brilliance.
Unlike sapphires, which are carefully cut down to reveal their utmost color and brilliance, these corundum are left in their larger forms, enabling designers to create jewelry on a bigger scale. Earrings—the statement jewelry for holiday—have long corundum drops, some translucent enough for light to pass through. Necklaces and bracelets often combine tonal shades of one of the colors. Others are being mixed, harmonized by virtue of their earthy palette.
Since these corundum specimens are larger in size than typical sapphires are, designers are letting the stones speak for themselves. Any precious metals, in particular 18K yellow or rose gold, are kept to a minimum, another nod to the naturalistic trend.
Their natural beauty though is so breath-taking and special, many designers are referring to these gems with the more familiar sapphire label.