It’s really pretty unusual for a major new gemstone to appear on the market. I only remember a couple in 40 years of this business. Tanzanite comes to mind. Cheap Chinese pearls is another. It’s easy to forget that this is a once in a decade sort of occurrence but a frequently overlooked one is Welo Opal in Ethiopia. The site was discovered in 2009 and the market has been slowly growing. Less known is that this is one of the largest opal deposits in the world. We’ll be seeing this material for decades or more.
Photos courtesy of Star Mountain Gems.
Welo opals are about 1/10 the price of their Australian equivalents that we’ve become accustomed to and that’s led to some curious lore. Are they crap? Are they kidding? Where’s the fine print?
To the extent that there’s fine print, it’s that they are what’s called ‘hydrophane’. That means they absorb water like a sponge. They give it up like a sponge too so you can dry them out just as easily as you can get them wet. When they’re wet, they lose the opalescence and that’s, well, weird. It’s easy enough to avoid by staying out of the pool with them, but it does freak people out and you can change the look if you soak them in wine or something else that leaves a residue.
Then there’s the translucency. I like it, but they don’t generally have that white opaque background that people have learned is the look of most Aussie stones. I see it as adding depth and a 3-D look to the play of color. You can see into and sometimes even through the stone sort of like what used to be called crystal opals. I’ve never seen a triplet or even a doublet.
It’s not all bad news. The hydrophane relationship with water has a feature. Opals are fragile, and Welo opals are no exception, but they’re far less prone to crazing. That’s the little spiderweb cracks that opals are famous for developing from just sitting around. One day they’re beautiful and the next they look like sugar cubes with play-of-color. There’s no real way to stop it and there’s no way to tell in advance if you’re stone is at risk.