Rarity in Mineral Records and the Story Behind Kyawthuite
Minerals number in the thousands, with roughly 6,000 cataloged worldwide, a figure confirmed by the International Mineralogical Association. These substances emerge from various geological processes and appear across many regions, yet a surprising portion shows up in tiny, isolated pockets. It remains unusual for a mineral to be represented by a single crystal fragment, even when the conditions for formation are favorable.
Even after minerals form, they can crack, weather, or disperse. The discovery of a mineral known from only a single sample is noteworthy and informative for scientists studying formation conditions and crustal chemistry.
That rarity applies to kyawthuite, a mineral with just one known fragment on Earth as of today. The lone specimen emerged as a gem-like shard near Mogok, Myanmar, and the International Mineralogical Association officially recognized it in 2015.
Before this natural specimen, a synthetic analogue existed, but the single natural example is housed at the Natural History Museum in Los Angeles, United States.
Less than one centimeter in length
Kyawthuite appears as a transparent reddish-orange mineral. The sole known specimen measures under one centimeter and weighs 1.61 carats (about 0.32 grams). Its chemical formula is Bi3+Sb5+O4 with trace tantalum. Bismuth and antimony are relatively uncommon metals, though not as rare as some imagine.
Geochemical data show that there is more bismuth in the Earth’s crust than gold, while antimony outnumbers silver in abundance. The rarity of kyawthuite results from not only the scarcity of its constituent elements but also the very specific mineral-forming environment required. Oxygen dominates crustal abundance, so kyawthuite’s occurrence reflects a precise set of conditions rather than merely its ingredients.
Because bismuth is heavy, kyawthuite has a density exceeding eight times that of water, and about twice that of ruby, which makes the tiny stone feel denser than its weight would suggest.
Kyawthuite stands as the only well-documented bismuth-antimony oxide mineral and bears the name of the late geologist Professor Kyaw Thu from Yangon University, Myanmar.
The kyawthuite specimen was found in a stream bed by sapphire hunters and was certified as a distinct mineral by the IMA in 2015. Its formal description appeared in 2017. (Citation: International Mineralogical Association, 2015; formal description 2017.)
Another strange mineral
Myanmar is not only the birthplace of kyawthuite. The country also yields another rare mineral, sometimes called the stone of pain, a precious stone of which only a handful of pieces have been discovered.
LiveScience notes that Caltech professor George W. Rosman explained how Myanmar’s abundance of precious stones ties to ancient geological processes. The pressure and heat generated when the Indian plate collided with Asia played a key role. Yet decades of conflict and sanctions have affected the region, and many of these rare gemstones may end up in non-scientific hands, limiting our full appreciation of their geological significance. (Citation: LiveScience, Rosman explanation on Myanmar geology.)
Notes: readers seeking deeper technical detail can consult postings from research institutions and museum records for comprehensive data on mineral identity, crystallography, and occurrence patterns. (Citation: mineralogical databases and museum catalogs.)