Mining company Metalex Ventures Ltd. recently claimed it had unearthed purple micro-diamonds from the property it’s prospecting in Quebec. The company said it has uncovered 649 diamonds, including nine rare purple stones, from the property. The announcement brought surprise and some skepticism in the colored-diamond community.

While most fancy colored diamonds are considered rare, purple diamonds are among the rarest of the rare, and attractive purple diamonds are even rarer, according to colored-diamond expert Alan Bronstein, of Aurora Gems.

“The purple diamonds I have seem to have a grayish or metallic tone,” he says. “The best ones are pinkish-purple or pink-purple, which still can appear purple to the eye, and brownish to brown-purple, which may look like the skin of a plum. You see very few of any of these colors in half-carat and larger. I believe the largest known stone is about five carats, and it’s not pretty at all.”

Bronstein notes that most purple diamonds are said to come from Russia, and there are fewer than 100 real purple diamonds in the world, about the same number as orange stones.

The famous Kobe Bryant “repentance” diamond was sometimes described as a purple stone, but also as purplish-pink and sometimes just pink.