Scientists from St. Petersburg University working with colleagues from other research institutions in Russia have studied the mineralogy of scoria cones and lava flows of fumaroles in Kamchatka. The objects were formed after a pair of major eruptions of the Tolbachik Volcano in 1975 through 1976 and 2012 through 2013. The area is considered unique for mineralogical diversity.
Over recent years scientists have discovered dozens of new minerals in the area, with many of them only found in the region. Recently scientists from St. Petersburg University discovered a new mineral dubbed petrovite, Na10CaCu2(SO4)8. Petrovite occurs as blue globular aggregates of tabular crystals that feature gaseous inclusions.
Prof. Oleg Siidra says the copper atom in the crystal structure of petrovite has a very rare coordination of seven oxygen atoms. That coordination is only known in a few compounds. The mineral consists of oxygen atoms, sodium sulfur, and copper, forming a porous framework. Voids in the mineral are connected by channels through which small sodium atoms can move.
Scientists were able to establish that the structured type of petrovite is promising for ionic conductivity. That opens the door for the material to be used as a cathode for sodium-ion batteries. Right now, the biggest challenge for using the mineral for battery cathodes is the small amount of transition metal, copper in this case, and the crystal structure.
Scientists believe that could be solved by synthesizing a compound with the same structure as petrovite in the laboratory. It’s not altogether uncommon for scientists to discover new minerals. Between 2008 and 2017, new minerals were discovered on the Kola Peninsula, in the Negev Desert in Israel, and in Greece, Tanzania, South Africa, Jordan, and many other locations.