Kankite is a

mineral In geology and mineralogy, a mineral or mineral species is, broadly speaking, a solid chemical compound with a fairly well-defined chemical composition and a specific crystal structure that occurs naturally in pure form.John P. Rafferty, ed. ( ...

with the chemical formula Fe³⁺ As O₄·3.5( H₂O). Kankite is named for the locality that yielded first specimens Kaňk,

Czech Republic The Czech Republic, or simply Czechia, is a landlocked country in Central Europe. Historically known as Bohemia, it is bordered by Austria to the south, Germany to the west, Poland to the northeast, and Slovakia to the southeast. The ...

. Kankite forms in old (1200- to 1400-year-old) mine dumps. It is yellowish-green on fresh exposure, with a paler greenish yellow on exposure to air.

Properties

Kankite is a monoclinic mineral, meaning it is a mineral system having 3 unequal axes of which one is at right angles with the other two. It has an uneven fracture and has a hardness of 2–3 (gypsum–calcite). It is translucent yellowish green in color with a grayish-yellow streak. Its luster is dull to vitreous. Kankite contains the elements arsenic, iron, hydrogen and oxygen.
Frost, Ray L. and Cejka, Jin and Keeffe, Eloise C. and Sejkora, Jiri (2009)''Raman Spectroscopic study of the mixed anion sulphate-arsenate mineral pamnauite''Journal of Raman Spectroscopy, 40(11) pp. 1547–1550. It was approved by the IMA in 1976. Its habit is botryoidal, "grape-like" rounded forms (e.g. malachite). It forms encrustations, crust-like aggregates on matrix. The specific gravity of Kankite is 2.70.

Occurrences

Kankite was first described in 1976 for an occurrence in the Kaňk,

Kutná Hora Kutná Hora (; medieval Czech: ''Hory Kutné''; german: Kuttenberg) is a town in the Central Bohemian Region of the Czech Republic. It has about 20,000 inhabitants. The centre of Kutná Hora, including the Sedlec Abbey and its ossuary, was designa ...

Bohemia Bohemia ( ; cs, Čechy ; ; hsb, Čěska; szl, Czechy) is the westernmost and largest historical region of the Czech Republic. Bohemia can also refer to a wider area consisting of the historical Lands of the Bohemian Crown ruled by the Bohem ...

, Czech Republic. It is a rare secondary mineral in highly weathered mine dumps containing

arsenopyrite Arsenopyrite ( IMA symbol: Apy) is an iron arsenic sulfide (FeAsS). It is a hard ( Mohs 5.5-6) metallic, opaque, steel grey to silver white mineral with a relatively high specific gravity of 6.1. When dissolved in nitric acid, it releases eleme ...

(in the Czech Republic). It occurs in association with

scorodite Scorodite is a common hydrated iron arsenate mineral, with the chemical formula FeAsO4·2H2O. It is found in hydrothermal deposits and as a secondary mineral in gossans worldwide. Scorodite weathers to limonite. Scorodite was discovered in the S ...

, pitticite,

parascorodite Parascorodite is a rare, secondary mineral, secondary iron-arsenate mineral. It has a chemical formula of () and was discovered in 1967 using X-ray powder diffraction methods, when an unknown substance was found along with scorodite on medieval or ...

, zykaite, arsenopyrite, vajdakite, native

arsenic Arsenic is a chemical element with the symbol As and atomic number 33. Arsenic occurs in many minerals, usually in combination with sulfur and metals, but also as a pure elemental crystal. Arsenic is a metalloid. It has various allotropes, but ...

pyrite The mineral pyrite (), or iron pyrite, also known as fool's gold, is an iron sulfide with the chemical formula Iron, FeSulfur, S2 (iron (II) disulfide). Pyrite is the most abundant sulfide mineral. Pyrite's metallic Luster (mineralogy), lust ...

proustite Proustite is a sulfosalt mineral consisting of silver sulfarsenide, Ag3 As S3, known also as light red silver or ruby silver ore, and an important source of the metal. It is closely allied to the corresponding sulfantimonide, pyrargyrite, from whi ...

gypsum Gypsum is a soft sulfate mineral composed of calcium sulfate dihydrate, with the chemical formula . It is widely mined and is used as a fertilizer and as the main constituent in many forms of plaster, blackboard or sidewalk chalk, and drywall. ...

, “

limonite Limonite () is an iron ore consisting of a mixture of hydrated iron(III) oxide-hydroxides in varying composition. The generic formula is frequently written as FeO(OH)·H2O, although this is not entirely accurate as the ratio of oxide to hydroxid ...

” and

quartz Quartz is a hard, crystalline mineral composed of silica (silicon dioxide). The atoms are linked in a continuous framework of SiO4 silicon-oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall chemical form ...

. It has also been reported from Munzig near

Meissen Meissen (in German orthography: ''Meißen'', ) is a town of approximately 30,000 about northwest of Dresden on both banks of the Elbe river in the Free State of Saxony, in eastern Germany. Meissen is the home of Meissen porcelain, the Albrecht ...

; from

Brand-Erbisdorf Brand-Erbisdorf () is a small town in the district of Mittelsachsen, in Saxony, Germany. It is situated 5 km south of Freiberg. As of 2020, the town has a population of 9,145. History The town is first mentioned in 1209 as ''Erlwinesberc'' ...

Saxony Saxony (german: Sachsen ; Upper Saxon: ''Saggsn''; hsb, Sakska), officially the Free State of Saxony (german: Freistaat Sachsen, links=no ; Upper Saxon: ''Freischdaad Saggsn''; hsb, Swobodny stat Sakska, links=no), is a landlocked state of ...

; from

Menzenschwand Menzenschwand (Alemannic: ''Menzèschwand'') is a climatic health spa in the Black Forest in Germany. The village lies within the borough of St. Blasien in the state of Baden-Württemberg. Geography Menzenschwand comprises three villages, ''V ...

Black Forest The Black Forest (german: Schwarzwald ) is a large forested mountain range in the state of Baden-Württemberg in southwest Germany, bounded by the Rhine Valley to the west and south and close to the borders with France and Switzerland. It is t ...

in Germany. It occurs at King's Wood mine,

Buckfastleigh Buckfastleigh is a market town and civil parish in Devon, England situated beside the Devon Expressway ( A38) at the edge of the Dartmoor National Park. It is part of Teignbridge and, for ecclesiastical purposes, lies within the Totnes Deanery. ...

Devon Devon ( , historically known as Devonshire , ) is a ceremonial and non-metropolitan county in South West England. The most populous settlement in Devon is the city of Plymouth, followed by Devon's county town, the city of Exeter. Devon is ...

, and from the South Terras mine, St. Stephen-in-Brannel,

Cornwall Cornwall (; kw, Kernow ) is a historic county and ceremonial county in South West England. It is recognised as one of the Celtic nations, and is the homeland of the Cornish people. Cornwall is bordered to the north and west by the Atlantic ...

in England. It has also been reported from the Suzukura mine north-northeast of

Enzan was a city located in Yamanashi Prefecture, Japan. The city was founded on April 5, 1954. As of 2003, the city had an estimated population of 25,856 and the density of 139.96 persons per km². The total area was 184.74 km². History On Novem ...

Yamanashi Prefecture is a prefecture of Japan located in the Chūbu region of Honshu. Yamanashi Prefecture has a population of 817,192 (1 January 2019) and has a geographic area of 4,465 km2 (1,724 sq mi). Yamanashi Prefecture borders Saitama Prefecture to the no ...

Japan Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the north ...

References

{{DEFAULTSORT:Kankite Iron(III) minerals Arsenate minerals Monoclinic minerals