Potassium minerals

Alum-(K) is a hydrous potassium aluminium sulfate mineral with formula KAl(SO4)2·12(H2O). It is the mineral form of potassium alum and is referred to as potassium alum in older sources. It is a member of the alum group.

Yingjiangite is a mineral named after its type locality in the Yingjiang county in 1990. It is a member of the phosphuranylite group.

Minyulite is a rare phosphate mineral with a chemical formula of (redefinition, IMA21-E).

Santite (KB5O8·4H2O) is a hydrated borate mineral of potassium found in Tuscany, Italy. It is named for Georgi Santi (1746–1823), a former director of the Museum of Natural History, Italy.

Zimbabweite is a yellow brown mineral with orthorhombic crystal habit and a hardness of 5, with formula . It is generally classed as an arsenite but is notable for also containing niobium and tantalum. It was discovered in 1986 in kaolinized pegmatite, i.e. weathered to clay, in Zimbabwe.

Rubicline, also referred to as Rb-microcline, is the rubidium analogue of microcline, an important tectosilicate mineral. Its chemical formula is (Rb, K)[AlSi3O8] with an ideal composition of RbAlSi3O8. Chemical analysis by electron microprobe indicated the average weight of the crystal is 56.66% SiO2, 16.95% Al2O3, and 23.77% Rb2O, along with trace amounts of caesium oxide (Cs2O) and iron(III) oxide (Fe2O3).

Leightonite is a rare sulfate mineral with formula of K2Ca2Cu(SO4)4•2H2O.

Ashcroftine-(Y) is an alkali yttrium calcium carbonate mineral with the chemical formula KNa(Y,Ca)SiO(OH)(CO)·8HO. It was first identified in southern Greenland and named after British mineral collector Frederick Noel Ashcroft.

Kremersite is a rare mineral which is a hydrated multiple chloride of iron, ammonium and potassium with the formula: (NH4,K)2FeCl5·H2O. Kremersite is a brown-red to orange mineral that crystallizes in the orthorhombic system. It is a water-soluble mineral that is found around volcanic fumaroles. Occurs at Vesuvius, Italy and Mount Etna, Sicily. It was discovered in 1853 and named for the German chemist, Peter Kremers (born 1827).

Hazenite is a hydrous phosphate mineral with chemical formula of , therefore a hydrous alkali magnesium phosphate. It is a member of the struvite group.

Gauthierite is a very rare mineral with the idealised chemical sum formula . It is a radioactive, hydrated orange-coloured lead potassium uranyl oxide hydroxide. It was found by analysing old mineral specimens, and is only known from one locality, the Shinkolobwe Mine in the Democratic Republic of the Congo. The mineral was named in honour of Gilbert Gauthier, a Belgian collector of uranium minerals, who provided a sample to one of the co-authors of the study that first identified it in 2017.

Taranakite is a hydrated alkali iron-aluminium phosphate mineral with the chemical formula .

Euchlorine (KNaCu3(SO4)3O) is a rare emerald-green sulfate mineral found naturally occurring as a sublimate in fumaroles around volcanic eruptions. It was first discovered in fumaroles of the 1868 eruption at Mount Vesuvius in Campania, Italy by Arcangelo Scacchi. The name 'euchlorine' comes from the Greek word meaning "pale green" in reference to the mineral's color, other reported spellings include euclorina, euchlorin, and euchlorite.

Kalinite is a mineral composed of hydrated potassium aluminium sulfate (a type of alum). It is a fibrous monoclinic alum, distinct from isometric potassium alum, named in 1868. Its name comes from kalium (derived from Arabic: القَلْيَه al-qalyah "plant ashes", which is the Latin name for potassium, hence its chemical symbol, "K".

Tarapacáite is the mineral form of potassium chromate with the chemical formula K2CrO4. It forms bright yellow crystals and was discovered in 1878. It is named for the former Tarapacá Province, Peru; nowadays belonging to Chile. The boundaries between Peru, Bolivia and Chile were vague in the Atacama Desert before the War of the Pacific (1879–1883). Its type locality is Oficina Maria Elena, Maria Elena, Tocopilla Province, Antofagasta Region, Chile. It is unlikely to occur anywhere except in highly arid conditions as it is easily soluble in water.

Chlorocalcite is a rare potassium calcium chloride evaporite mineral with formula: KCaCl3. It is found in active volcanic fumaroles.

Mathesiusite is a sulfate mineral containing potassium, vanadium, and uranium and has the chemical formula: K5(UO2)4(SO4)4(VO5)·4(H2O). It is a secondary mineral formed during post-mining processes.

Brammallite is a sodium-rich analogue of illite. First described in 1943 for an occurrence in Llandybie, Wales, it was named for British geologist and mineralogist Alfred Brammall (1879–1954).

thumb | right | alt=A sample of charoitite with frankamenite, Siberia, Russia | A sample of charoitite with frankamenite, Siberia, Russia Frankamenite is the fluorine-dominate variation of the rare mineral canasite with a general formula of K3Na3Ca5(Si12O30)[F,(OH)]4·(H2O).

The ferrierite group of zeolite minerals (the FER structure) consists of four very similar species: ferrierite-Mg, ferrierite-Na, ferrierite-NH4 and ferrierite-K, based on the dominant cation in the A location. ferrierite-Mg and ferrierite-K are orthorhombic minerals and ferrierite-Na is monoclinic with highly variable cationic composition . Calcium and other ions are often also present. They are found in vitreous to pearly, often radiating, spherical aggregates of thin blade-shaped transparent to translucent crystals.

Altisite (IMA symbol: Ati) is an exceedingly rare alkaline titanium aluminosilicate chloride mineral with formula Na3K6Ti2Al2Si8O26Cl3, from alkaline pegmatites. It is named after its composition (ALuminium, TItanium, and SIlicon).

Antipinite (IMA symbol: Atp) is a rare alkali Copper oxalate mineral with the chemical formula . Its type locality is the Tarapacá Region in Chile.

Colimaite, the naturally occurring analog of synthetic K3VS4, is a sulfide mineral discovered in southwestern Mexico. The potassium-vanadium sulfide was collected from the crater of the Colima volcano. The mineral colimaite is named after the locality of this volcano and has been approved in 2007, along with its mineral name, by the Commission on New Minerals, Nomenclature and Classification (CNMNC). It has been given the International Mineralogical Association number of IMA 2007–045.

Klöchite is a cyclosilicate mineral of the Osumilite Group, found in a basalt quarry in Klöch, Austria. The basalt quarry it was found in is part of the Styrian Basin Volcanic Field in south-eastern Austria. Klöchite was found to be hosted in a xenolith primarily composed of quartz, sanidine, and diopside. Very few vesicles in the xenolith held Klöchite crystals, and only two samples were taken for study.

Alsakharovite-Zn (IMA symbol: Ask-Zn) is an extremely rare alkaline strontium zinc titanium silicate mineral from the cyclosilicates class, with the chemical formula , from alkaline pegmatites. It belongs to the labuntsovite group.

Carlosruizite is a sulfate or selenate–iodate mineral with chemical formula: K6(Na,K)4Na6Mg10(SeO4)12(IO3)12·12H2O. It has a low density (specific gravity of 3.36), colorless to pale yellow, transparent mineral which crystallizes in the trigonal crystal system. It forms a series with fuenzalidaite.

Zircophyllite is a complex mineral, formula . It crystallizes in the triclinic – pinacoidal crystal class as dark brown to black micaceous plates. It has perfect 001 cleavage, a Mohs hardness of 4 to 4.5 and a specific gravity of 3.34. Its indices of refraction are nα=1.708 nβ=1.738 nγ=1.747 and it has a 2V optical angle of 62°.

Achyrophanite ((K,Na)3(Fe3+,Ti,Al,Mg)5O2(AsO4)5) is a yellow mineral, discovered in 2018 and described in 2025.

Andrianovite is a very rare mineral of the eudialyte group, with formula Na12(K,Sr,Ce)6Ca6(Mn,Fe)3Zr3NbSi(Si3O9)2(Si9O27)2O(O,H2O,OH)5. The original formula was extended to show the presence of cyclic silicate groups and silicon at the M4 site, according to the nomenclature of eudialyte group. Andrianovite is unique among the eudialyte group in being potassium-rich (other eudialyte-group species with essential K are davinciite and rastsvetaevite). It is regarded as potassium analogue of kentbrooksite, but it also differs from it in being oxygen-dominant rather than fluorine-dominant. Also, the

Rastsveatevite is a rare mineral of the eudialyte group with the chemical formula . Its structure is modular. It is only the third member of the group after andrianovite and davinciite with essential (site-dominating) potassium. Potassium and sodium enter both N4 and M2 sites. The mineral is named after Russian crystallographer Ramiza K. Rastsvetaeva.

Dachiardite-K is a rare zeolite-group mineral with the formula K4(Si20Al4O48)•13H2O. It is the potassium-analogue of dachiardite-Ca and dachiardite-Na, as suggested by the suffix "-K". Dachiardite honors Italian geologist and mineralogist Antonio D'Achiardi. In 1906, his son and mineralogist Giovanni D'Achiardi described and named the mineral dachiardite after he discovered it in a granitic pegmatite.

thumb | right Plavnoite is a rare complex uranium sulfate mineral with the formula K0.8Mn0.6[(UO2)2O2(SO4)]•3.5H2O. Typically for the secondary uranium mineral, plavnoite contains uranyl groups. It was discovered in the Plavno mine in Jáchymov, Czech Republic. The Jáchymov site is known as a type locality for many rare and unique minerals.

Davinciite is a very rare mineral of the eudialyte group, with the simplified formula Na12K3Ca6Fe32+Zr3(Si26O73OH)Cl2. The formula given does not show the presence of cyclic silicate groups. The mineral was named after Leonardo da Vinci to refer to the atypical geometrical forms he tended to use, compared by the authors of the mineral description to the atypical (not ideally centrosymmetrical) geometry of the Davinciite structure. The other quite atypical feature of Davinciite is its lavender colour, while the typical eudialyte is rather pink or red.