Akhtenskite is a manganese oxide mineral with the chemical formula of MnO2 (or: ε-Mn4+O2[4]) that was named after the Akhtensk deposit in Russia, where it was first discovered and noted in 1979.
[3] It can be found in the Akhtensk brown ironstone deposit, in the southern Ural Mountains, on Mt.
[2] Its crystals are usually hexagonal in shape, with flakiness and plating, usually because it replaced a mineral.
It occurs in mixtures with "psilomelane" (recently renamed to romanechite) and with other manganese oxides in an iron oxide deposit, most likely bacterially altered from a previous mineral in the Akhtensk deposit.
Some minerals that are commonly associated with akhtenskite are: todorokite, pyrolusite, nsutite, goethite, and cryptomelane.