Pseudolyonsite, Cu3(VO4)2, a new mineral species from the Tolbachik volcano, Kamchatka Peninsula, Russia

Scientists have discovered pseudolyonsite, Cu3(VO4)2, a new mineral species from the Tolbachik volcano in Kamchatka, Russia. This dark red to black mineral, found in medium-temperature fumaroles, exhibits unique characteristics such as flexibility in thin needles and distinct anisotropy under reflected light. Pseudolyonsite is isostructural with synthetic Cu3(VO4)2 and dimorphous with triclinic mcbirneyite, featuring a complex crystal structure composed of corrugated octahedral layers connected by VO4 tetrahedra. The mineral's name reflects its visual similarity to lyonsite, another vanadate mineral. The discovery was made through detailed analysis using electron probe microscopy and X-ray diffraction, providing insights into the mineral's composition, structure, and properties.

Zelenski, M. E., Zubkova, N. V., Pekov, I. V., Boldyreva, M. M., Yu. Pushcharovsky, D., & Nekrasov, A. N. (2011). Pseudolyonsite, Cu3(VO4)2, a new mineral species from the Tolbachik volcano, Kamchatka Peninsula, Russia. European Journal of Mineralogy, 23(3), 475–481. https://doi.org/10.1127/0935-1221/2011/0023-2101