There’s a mineral so uncommon that just one specimen of it has ever been present in the whole world.
It’s known as kyawthuite (cha-too-ite), a tiny, tawny-hued grain weighing only a third of a gram (1.61 carats). On first look, you would possibly mistaken it for amber or topaz; however the unassuming mineral speck has worth past measure.
The stone itself was bought in 2010 at a market in Chaung-gyi in Myanmar by gemologist Kyaw Thu, who thought the uncooked gem was a mineral known as scheelite. After he faceted the stone, although, he realized that he was taking a look at one thing uncommon.
Unable to match the mineral with something identified, he despatched it to the Gemological Institute of America (GIA) Laboratory in Bangkok, Thailand. There, mineralogists have been capable of relate the stone to artificial BiSbO4 – bismuth antimonate – although with the system Bi3+Sb5+O4, an association by no means earlier than present in nature.
“This is the primary on the earth. It is just not present in different international locations,” Thu instructed The Myanmar Times in 2016.
“From finding out within the area and shopping for stones from the Khanae market, [I could tell that] this stone was somewhat unusual and I purchased it. Then, after I reached Yangon, I examined it [and determined that] this was not like every other gem we have ever discovered.”
We do not know a lot in regards to the stone itself. It has a saturated orange colour, with a purple overtone and a white streak; that is the colour of the powder the gem produces when it’s dragged throughout a rough floor. It additionally has hole, tube-shaped inclusions known as en echelon veins which might be attributable to shear stress – proof of its pure formation.
Geologists assume that was possible igneous in origin, an inclusion in a kind of widespread volcanic rock known as pegmatite, widespread within the area the place the stone was discovered. Like granite, pegmatite’s composition is much like that of a fruit cake, with completely different minerals jumbled in; it’s normal to seek out giant crystals of gems in pegmatite.
Traces of titanium, niobium, tungsten, and uranium within the kyawthuite are in line with a pegmatite formation. Additionally, experiments within the lab present that bismuth antimonite crystals kind at excessive temperatures in line with the temperatures of cooling magma. Since the mineral seems to be so uncommon, there are possible different particular circumstances about the way it kinds, however we do not know what they’re.
The worth of kyawthuite is presently listed as priceless. The world’s second-rarest gem, a mineral known as painite, is valued at US$50,000 to $60,000 a carat. Oof.
The world’s solely identified piece of kyawthuite is presently housed safely on the National History Museum of Los Angeles County.
