Most human eyes have seen the mystical beauty of quartz, possibly without knowing it is the most common mineral on Earth, but which is the rarest?
When people want to possess something unique it usually has to be human-made, not a piece of the Earth. After all, we live on a large planet, and if geologic forces produce a particular mineral in one spot, there’s a pretty good chance it will be made somewhere else too. Indeed, of the 6,000 minerals recognized by the International Mineralogical Association (IMA), many are formed by multiple processes, with quite different chemistry leading to identical outcomes.
Even if a mineral did only form once, samples could easily be broken up and dispersed over a wide area. Consequently, it’s somewhat remarkable any mineral would be known from just a single sample. However, that’s the case for one crystal, kyawthuite.
Kyawthuite has only been found in the form of a single gemstone from near Mogok, Myanmar. Caltech's mineral database describes it as a small (1.61-karat) deep orange gemstone that the IMA officially recognized in 2015. An almost identical synthetic compound was already known, so if you badly want some, you don’t need to steal the single specimen from the Natural History Museum of Los Angeles County, where it is stored.
Interestingly, Myanmar is also the source of the second rarest mineral - painstone - a gemstone with only a handful recorded. Speaking to LiveScience, Caltech Professor George Rossman attributed the abundance of gemstones in Myanmar to the pressure and heat produced when India collided with Asia.