Which of these minerals is the rarest in the world?
Painite is a very rare borate mineral. It was first found in Myanmar by British mineralogist and gem dealer Arthur C.D. Pain who misidentified it as ruby until it was discovered as a new gemstone in the 1950s. When it was confirmed as a new mineral species, the mineral was named after him.
The chemical makeup of painite contains calcium, zirconium, boron, aluminium and oxygen (CaZrAl9O15(BO3)). The mineral also contains trace amounts of chromium and vanadium, which are responsible for Painite's typically orange-red to brownish-red color, similar to topaz. The crystals are naturally hexagonal in shape, and, until late 2004, only two had been cut into faceted gemstones.