There is a mine that is so rare that there is only one example of it in the whole world. It is called kyawtuite (cha-too-ite), a small brownish-brown grain weighing only one-third of a gram (1.61 carats). At first glance you might mistake it for amber or topaz; but an inconspicuous grain of metal has immeasurable value.

The stone itself was purchased from a market in Chaung Gi, Myanmar, in 2010 by gemologist Kyaw Tu, who believed the rough gemstone was a mineral called scheelite. It was only after he cut the stone that he realized he was looking at something unusual.

Unable to match the mineral to anything known, he sent it to the Gemological Institute of America (GIA) laboratory in Bangkok, Thailand. There mineralogists managed to associate the stone with synthetic BiSbO.₄ – bismuth antimonate – Albeit with the formula Bi³⁺sb⁵⁺HE₄A structure that has not been found in nature before.

“Surveying in the field and purchasing stones from the Khanae Market, [я міг зрозуміти, що] This stone was a bit strange and I bought it. Then when I got to Yangon I researched [і визначив, що] “It’s unlike any jewel we’ve ever found.”

We know very little about the stone itself. It has a rich orange color with a red tint and white veins; It is the color of the powder that forms the gem when dragged over a rough surface. It also has hollow tubular inclusions called veins. stepped typeIt is caused by shear stress, which shows its natural formation.

Geologists believe it is likely of igneous origin, being incorporated into a type of common volcanic rock called pegmatite, which is common in the area where the stone was found. Like granite, the composition of pegmatite is like a fruitcake with different minerals mixed together; Large gemstone crystals are often found in pegmatite.

Traces of titanium, niobium, tungsten and uranium at Kyawtuit indicate pegmatite formation. Furthermore, experiments in the laboratory show that bismuth antimonide crystals form at high temperatures corresponding to the temperatures of cooling magma. Since the mineral appears to be so rare, it is likely that there were other special conditions for its formation, but we do not know what they were.

The value of Kyawtuit is now considered priceless. The peinite mineral, the second rarest gemstone in the world, is worth between $50,000 and $60,000 per carat. The only known Kiawtuit piece in the world is now safely stored at the Los Angeles County National Museum of History.