Arakiite (
IMA symbol
A symbol is a mark, sign, or word that indicates, signifies, or is understood as representing an idea, object, or relationship. Symbols allow people to go beyond what is known or seen by creating linkages between otherwise very different conc ...
:
Ark
Ark or ARK may refer to:
Biblical narratives and religion Hebrew word ''teva''
* Noah's Ark, a massive vessel said to have been built to save the world's animals from a flood
* Ark of bulrushes, the boat of the infant Moses
Hebrew ''aron''
* ...
) is a rare mineral with the formula (Zn,Mn
2+)(Mn
2+,Mg)
12(Fe
3+,Al)
2(As
3+O
3)(As
5+O
4)
2(OH)
23. It is both
arsenate
The arsenate ion is .
An arsenate (compound) is any compound that contains this ion. Arsenates are salts or esters of arsenic acid.
The arsenic atom in arsenate has a valency of 5 and is also known as pentavalent arsenic or As(V).
Arsenate resem ...
and
arsenite
In chemistry, an arsenite is a chemical compound containing an arsenic oxyanion where arsenic has oxidation state +3. Note that in fields that commonly deal with groundwater chemistry, arsenite is used generically to identify soluble AsIII anions. ...
mineral, a combination that is rare in the world of minerals. Arakiite is stoichiometrically similar to
hematolite. It is one of many rare minerals coming from the famous
Långban
Långban is a mining area in Värmland in Sweden. It belongs to Filipstad Municipality, with the nearest city being Filipstad, 21 km south. It was systematically mined through 1711-1972, but has traces from the 15th century. It is the birthp ...
manganese
skarn
Skarns or tactites are hard, coarse-grained metamorphic rocks that form by a process called metasomatism. Skarns tend to be rich in calcium-magnesium-iron-manganese-aluminium silicate minerals, which are also referred to as calc-silicate minerals ...
deposit in Sweden. Other minerals bearing both arsenite and zinc include
kraisslite and
mcgovernite.
The mineral crystallizes in the
monoclinic crystal system
In crystallography, the monoclinic crystal system is one of the seven crystal systems. A crystal system is described by three vectors. In the monoclinic system, the crystal is described by vectors of unequal lengths, as in the orthorhombic sy ...
in space group ''Cc''.
References
Zinc minerals
Manganese(II) minerals
Iron(III) minerals
Arsenate minerals
Monoclinic minerals
Minerals in space group 9
Minerals described in 2000
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