Akhtenskite is a

manganese Manganese is a chemical element with the symbol Mn and atomic number 25. It is a hard, brittle, silvery metal, often found in minerals in combination with iron. Manganese is a transition metal with a multifaceted array of industrial alloy use ...

oxide mineral The oxide mineral class includes those minerals in which the oxide anion (O2−) is bonded to one or more metal alloys. The hydroxide-bearing minerals are typically included in the oxide class. The minerals with complex anion groups such as the si ...

with the chemical formula of MnO₂ (or: ε-Mn⁴⁺O₂) that was named after the Akhtensk deposit in

Russia Russia (, , ), or the Russian Federation, is a List of transcontinental countries, transcontinental country spanning Eastern Europe and North Asia, Northern Asia. It is the List of countries and dependencies by area, largest country in the ...

, where it was first discovered and noted in 1979. It can be found in the Akhtensk brown ironstone deposit, in the southern

Ural Mountains The Ural Mountains ( ; rus, Ура́льские го́ры, r=Uralskiye gory, p=ʊˈralʲskʲɪjə ˈɡorɨ; ba, Урал тауҙары) or simply the Urals, are a mountain range that runs approximately from north to south through western ...

, on Mt. Zarod, on the

Sikhote-Alin Mountains The Sikhote-Alin (russian: Сихотэ́-Али́нь, , , ) is a mountain range in Primorsky and Khabarovsk Krais, Russia, extending about to the northeast of the Russian Pacific seaport of Vladivostok. The highest summits are Tordoki Yani at ...

, and in the

Primorskiy Krai Primorsky Krai (russian: Приморский край, r=Primorsky kray, p=prʲɪˈmorskʲɪj kraj), informally known as Primorye (, ), is a federal subject (a krai) of Russia, located in the Far East region of the country and is a part of the ...

, all in Russia. Its crystals are usually hexagonal in shape, with flakiness and plating, usually because it replaced a mineral. Akhtenskite is a polymorphous with the much more widespread

pyrolusite Pyrolusite is a mineral consisting essentially of manganese dioxide ( Mn O2) and is important as an ore of manganese.. It is a black, amorphous appearing mineral, often with a granular, fibrous, or columnar structure, sometimes forming reniform ...

. 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. It also occurs in crusts of ferromanganese minerals on oceanic rocks. Its chemical makeup is 63%

oxygen Oxygen is the chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements as wel ...

and 37%

. Some minerals that are commonly associated with akhtenskite are:

todorokite Todorokite is a rare complex hydrous manganese oxide mineral with the chemical formula . It was named in 1934 for the type locality, the Todoroki mine, Hokkaido, Japan. It belongs to the prismatic class 2/m of the monoclinic crystal system, but ...

nsutite Nsutite is a manganese oxide mineral with formula: ( Mn4+1−xMn2+x O2-2x(O H)2x where x = 0.06-0.07).http://www.webmineral.com/data/Nsutite.shtml Webmineral data It is found in most large manganese deposits and was first discovered in Nsuta, Ghan ...

goethite Goethite (, ) is a mineral of the diaspore group, consisting of iron(III) oxide-hydroxide, specifically the "α" polymorph. It is found in soil and other low-temperature environments such as sediment. Goethite has been well known since ancient t ...

, and

cryptomelane Cryptomelane is a potassium manganese oxide mineral with formula K(Mn4+,Mn2+)8O16. In 1942 the name ''cryptomelane'' was proposed as part of an effort to sort out the manganese oxide minerals referred to as ''psilomelane''. Cryptomelane was identi ...

References

Manganese(IV) minerals Oxide minerals {{oxide-mineral-stub