Cupromolybdite, Cu3O(MoO4)2, a new fumarolic mineral from the Tolbachik volcano, Kamchatka Peninsula, Russia

Researchers have discovered cupromolybdite, a new fumarolic mineral, at the Tolbachik volcano on Kamchatka's Peninsula. This honey-yellow to brown mineral, characterized by its adamantine lustre and brittle nature, forms prismatic or acicular crystals often found in radiating aggregates. Cupromolybdite's chemical composition, Cu₃O(MoO₄)₂, was determined through electron microprobe analysis, revealing a unique structure with strings of corner-shared Cu(1)O₆ octahedra. The mineral is associated with various other fumarolic minerals and serves as a natural analogue to the synthetic compound Cu₃Mo₂O₉, while also being an S-free counterpart to vergasovaite. Its orthorhombic crystal structure was solved using single-crystal data, providing insights into its atomic arrangement.

Zelenski, M. E., Zubkova, N. V., Pekov, I. V., Polekhovsky, Y. S., & Pushcharovsky, D. Y. U. (2012). Cupromolybdite, Cu3O(MoO4)2, a new fumarolic mineral from the Tolbachik volcano, Kamchatka Peninsula, Russia. European Journal of Mineralogy, 24(4), 749–757. https://doi.org/10.1127/0935-1221/2012/0024-2221