A rare mineral called kyawthuite, found only in Myanmar, has left experts puzzled due to its unique composition never before seen in nature. Gemologist Kyaw Thu discovered this tiny, tawny-hued grain weighing just a third of a gram in 2010, mistaking it for another mineral initially. After further examination, researchers at the Gemological Institute of America identified it as synthetic BiSbO4. The mineral’s formation in pegmatite rock and the presence of various elements suggest a high-temperature origin. With only one known specimen in the world, kyawthuite’s value is considered priceless, rivaling even the rarest gems like painite.
https://www.sciencealert.com/the-worlds-rarest-mineral-is-so-rare-its-only-ever-been-found-once