There was a time when people might have automatically assumed diamonds are the world’s rarest gem, given their price and association with wealth.
That’s not the case, however, and interestingly, diamonds have never been the rarest gem on the planet.
The world’s actual rarest gemstone is kyawthuite, which is known from just one sample. The transparent, reddish-orange mineral is housed at the Natural History Museum of Los Angeles County.
The sample was found near Mogok, Myanmar, and was recognized by the International Mineralogical Association (IMA) in 2015. It was cut into a 1.61-carat gemstone for study, and experts have found that it likely formed in pegmatite.
It as an asymmetrical structure and a Mohs hardness of 5.5.
Having only a single sample of a mineral or gemstone is exceedingly rare, because even if it is only likely to be formed in a single place, there should still be a few pieces.
Kyawthuite is made of bismuth, antimony, and oxygen, with traces of tantalum. None of these metals are common, but neither are they so rare that the makeup could explain the single sample.
Bismuth is more common than gold, and antimony is moreso than silver, so the rarity of kywathuite must be due to how and where it forms.
Myanmar is also home to painite, the world’s second rarest mineral, of which we have only a handful of samples, as well as jadeite, the toughest mineral known to man.
So, the country definitely seems to be the place to check the ground for something you’ve never seen before – and might never see again.
If you thought that was interesting, you might like to read a story that reveals Earth’s priciest precious metal isn’t gold or platinum and costs over $10,000 an ounce!