by Most human eyes have seen the mystical beauty of quartz, perhaps unaware that it is the most common mineral on Earth, but which is the rarest?
Minerals are scattered all over our planet, from glistening specks in gravel or sand to real hidden gems. According to Geological Society of the United States (opens in a new tab)minerals are naturally occurring inorganic elements or compounds, that is, they do not contain carbon. Each type of mineral exhibits an order in its internal structure and has a unique chemical composition. The form a mineral’s crystals take, as well as its other physical properties, can vary.
The rarest mineral on Earth is kyawthuite. Only one crystal, found in the Mogok region of Myanmar, is known to exist. Caltech Mineral Database (opens in a new tab) describes it as a small dark orange gemstone (1.61 carat) that the International Mineralogical Association (opens in a new tab) officially recognized in 2015.
However, not much is known about kyawthuite, so let’s move on to the second rarest mineral in existence. This is painite, which appears as dark red hexagonal crystals (although there are some pinkish exceptions). Although painite is now more easily found than it was before, this mineral is still rare and its chemical structure makes it a scientific enigma.
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In 1952, English gemstone collector and dealer Arthur Pain acquired two crimson crystals in Myanmar, according to George Rossman (opens in a new tab)professor of mineralogy at CalTech, who has researched painite since the 1980s and maintains an extensive database (opens in a new tab) of all the samples he analyzed under the microscope.
Pain thought the crystals were rubies, which the area is famous for, but unbeknownst to him they were actually something much rarer.
Painite (which took Arthur’s surname) is sometimes unearthed with rubies and other gemstones. This explains why Pain assumed the crystals were rubies when, according to Rossman, he gave them to the British Museum in 1954 for further study. Another sample of painite from Myanmar surfaced in 1979, and until 2001 these three crystals were the only known specimens of painite in the world.
The very first painite crystal discovered, known as painite #1, was later analyzed by Rossman. His latest study on pain was published in Mineralogical magazine (opens in a new tab) in 2018.
“I drove [studies] from [first] sample,” he told Live Science.[My results] have become the standards by which other discoveries of painite have been confirmed.”
It was through this research that Rossman determined what elements make up painite. With infrared spectroscopy, infrared radiation is used to identify elements based on how they absorb, reflect, and emit that light. With Raman spectroscopy, a laser is used to scatter visible, infrared, or ultraviolet light, causing molecules to emit unique vibrations that make them identifiable.
Rossman also discovered that there was an error in the chemical composition originally determined by British Museum scientists. While they correctly identified aluminum, boron, calcium, and oxygen, the element zirconium was missing. Another thing Rossman discovered was what gave painite its reddish tint; It contains traces of vanadium and chromium which could make it appear deceptively like a ruby.
But what makes painite so rare? On the one hand, it is only found in Myanmar, but the real reason lies in its formation. Painite is a borate crystal, which means it contains boron. It also contains zirconium. Boron has difficulty bonding with zirconium. In fact, painite is the only mineral in which the two have been found linked in nature. Although the reason is still unclear, zirconium and boron have not been found together in significant concentrations, as Rossman said. It is also believed that these elements may not be very stable together relative to other elements they might bond with.
“To my knowledge, no one has done a serious study of what it takes to form painite,” Rossman said. “I don’t know of any attempt at synthesis in a lab.”
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Why Burma?
What Rossman has an idea is why painite and so many other gemstones, such as kyawthuite, are found in Myanmar. When the former supercontinent of Gondwana began to split about 180 million years ago, India slid north and collided with what is now South Asia. The pressure and heat from the collision formed a treasure trove of rocks, including many gems. He thinks the boron in painite and other borate minerals may have come from shallow seas around the newly formed landmass.
Rossman had numerous crystals that were suspected to be painite sent to him for identification. Some have been hidden in plain sight for decades, as they were often hidden in bags of rough gemstones or in the hands of dealers and collectors who misidentified them.
Painite suitable for luxury jewelry is hard to find and fetches up to $60,000 a carat, Rossman said. What determines the price can be subjective, but the fewer the flaws, the better.
It should be noted that there are ethical concerns about mining in Myanmar, which is also famous for other gemstones and specimens of tiny prehistoric creatures trapped in amber. Human Rights Watch (opens in a new tab) raises awareness of human rights violations by the military government, which profits from the mining industry, which has dangerous and disease-infested mines, forced labor and child labor. Some jewelry companies refuse to buy gemstones mined there for this reason and some scientists refuse to study specimens (opens in a new tab) from this country.
Painite is now more common than it once was. Several crystals began to appear in 2005, all in that year, and most painites are now found in the Wet Loo and Therein Taung regions of Myanmar.
Although painite no longer wears the crown of the rarest mineral, it is still a real gem.
