Category
page 5Monoclinic minerals

lavendulan
Lavendulan is an uncommon arsenate mineral in the lavendulan group. It is known for its characteristic intense electric blue colour. Lavendulan is very similar to lemanskiite, the analogue trihydrate mineral, to the point of them being considered dimorphs. Lemanskiite is tetragonal, but lavendulan is monoclinic. Lavendulan has the same structure as sampleite, and the two minerals form a series. It is the calcium analogue of zdenĕkite and the arsenate analogue of sampleite.
annite
Annite is a phyllosilicate mineral in the mica family. It has a chemical formula of KFe32+AlSi3O10(OH)2. Annite is the iron end member of the biotite mica group, the iron rich analogue of magnesium rich phlogopite. Annite is monoclinic and contains tabular crystals and cleavage fragments with pseudohexagonal outlines. There are contact twins with composition surface {001} and twin axis {310}.
rozenite
Rozenite is a hydrous iron sulfate mineral, Fe2+SO4·4(H2O).
birnessite
Birnessite (nominally MnO2·nH2O), also known as δ-, is a hydrous manganese dioxide mineral with a chemical formula of Na0.7Ca0.3Mn7O14·2.8H2O. It is the main manganese mineral species at the Earth's surface, and commonly occurs as fine-grained, poorly crystallized aggregates in soils, sediments, grain and rock coatings (e.g., desert varnish), and marine ferromanganese nodules and crusts. It was discovered at Birness, Aberdeenshire, Scotland.
wagnerite
Wagnerite is a mineral, a combined phosphate and fluoride of iron and magnesium, with the formula . It occurs in pegmatite associated with other phosphate minerals. It is named after Franz Michael von Wagner (1768–1851), a German mining official in Munich.
christite
Christite is a mineral with the chemical formula TlHgAsS3. It is named after Dr. Charles L. Christ, a member of the U.S. Geological Survey. It usually comes in a crimson red or bright orange color. It has a density of 6.2 and has a rating between 1 and 2 on Mohs Hardness Scale. Christite has an adamantine luster and leaves behind an orange streak. Its crystal system is monoclinic with possible crystal classes of twofold symmetry, mirror plane symmetry, and twofold with a mirror plane. This means it can have radial symmetry, mirror plane symmetry, or mirror plane symmetry perpendicular to the t
masuyite
Masuyite is a uranium/lead oxide mineral with formula Pb[(UO2)3O3(OH)2]·3H2O.
suanite
Suanite is a magnesium borate mineral with formula Mg2B2O5.
syngenite
Syngenite is an uncommon potassium calcium sulfate mineral with formula K2Ca(SO4)2·H2O. It forms as prismatic monoclinic crystals and as encrustations.
kaersutite
Kaersutite is a dark brown to black double-chain calcic titanium-bearing amphibole mineral with formula: NaCa2(Mg3Ti4+Al)(Si6Al2)O22(O)2.
anthonyite
Anthonyite is a hydrous secondary copper halide mineral with chemical formula of .
arthurite
Arthurite is a mineral composed of divalent copper and iron ions in combination with trivalent arsenate, phosphate and sulfate ions with hydrogen and oxygen. Initially discovered by Sir Arthur Russell in 1954 at Hingston Down Consols mine in Calstock, Cornwall, England, arthurite is formed as a resultant mineral in the oxidation region of some copper deposits by the variation of enargite or arsenopyrite. The chemical formula of Arthurite is CuFe23+(AsO4,PO4,SO4)2(O,OH)2·4H2O.
switzerite
Switzerite is a mineral with the chemical formula of (Mn)3(PO4)2·7H2O. The mineral was named after George Switzer, former Curator of Minerals at the US National Museum. The mineral is monoclinic prismatic, meaning that it has one mirror plane, one 2-fold rotation axis which is perpendicular to the mirror plane and a center of symmetry. Switzerite is a part of the monoclinic space group P 21/a. For its optical properties, Switzerite is classified as anisotropic, has a low surface relief and birefringence of δ = 0.020.
livingstonite
Livingstonite is a mercury antimony sulfosalt mineral. It occurs in low-temperature hydrothermal veins associated with cinnabar, stibnite, sulfur and gypsum.
bílinite
Bílinite (Fe2+Fe23+(SO4)4·22H2O) is an iron sulfate mineral. It is a product of the oxidation of pyrite in water. It is an acidic mineral that has a pH of less than 3 and is harmful to the environment when it comes from acid rock drainage (Keith et al., 2001).
yttrialite-(Y)
Yttrialite or Yttrialite-(Y) is a rare yttrium thorium sorosilicate mineral with formula: (Y,Th)2Si2O7. It forms green to orange yellow masses with conchoidal fracture. It crystallizes in the monoclinic-prismatic crystal system. It has a Mohs hardness of 5 to 5.5 and a specific gravity of 4.58. It is highly radioactive due to the thorium content.

leonite
Leonite is a hydrated double sulfate of magnesium and potassium. It has the formula K2SO4·MgSO4·4H2O. The mineral was named after Leo Strippelmann, who was director of the salt works at Westeregeln in Germany. The mineral is part of the blodite group of hydrated double sulfate minerals.
esperite
Esperite is a rare complex calcium lead zinc silicate (PbCa3Zn4(SiO4)4) related to beryllonite and trimerite that used to be called calcium larsenite.
sartorite
Sartorite is a lead arsenic sulfide with the chemical formula PbAs2S4 and as type locality the Lengenbach Quarry in Legenbach, Binnental, Valais, Switzerland. Historically, sartorite has been thought isomorphic to chalcostibite, emplectite, and zinckenite, but was definitively distinguished from the others in 1939.
pääkkönenite
Pääkkönenite is a metallic grey mineral with the molecular formula Sb2AsS2. It is named after Veikko Pääkkönen (1907–1980), a Finnish geologist.
samsonite
sulfosalt mineral
sabinaite
Sabinaite (Na4Zr2TiO4(CO3)4) is a rare carbonate mineral. It crystallizes in the monoclinic crystal system as colorless to white prisms within cavities. It is more typically found as powdery coatings and masses. It has a specific gravity of 3.36.
lansfordite
Lansfordite is a mineral of magnesium carbonate (). It represents the pentahydrate of magnesium carbonate, and has the total formula . Landsfordite was discovered in 1888 in a coal mine in Lansford, Pennsylvania. It crystallizes in the monoclinic system (space group P21/c) and typically occurs as colorless to white prismatic crystals and stalactitic masses. It is a soft mineral, Mohs hardness of 2.5, with a low specific gravity of 1.7. It is transparent to translucent with refractive indices of 1.46 to 1.51. The mineral will effloresce at room temperature, producing nesquehonite.
kogarkoite
Kogarkoite is a sodium sulfate fluoride mineral with formula Na3(SO4)F. It has a pale blue color, a specific gravity of about 2.67 and a hardness of 3.5. The crystal is monoclinic and is a type of naturally occurring antiperovskite. Kogarkoite is named after the Russian petrologist Lia Nikolaevna Kogarko (born 1936) who discovered the mineral.
kröhnkite
Kröhnkite ( Na2Cu(SO4)2•2H2O ) is a rare copper sulfate mineral named after B. Kröhnke who first researched it. Kröhnkite may be replaced by Saranchinaite, the anhydrous form of the mineral, if heated to temperatures above 200 °C (392 °F).
fraipontite
Fraipontite is a zinc aluminium silicate mineral with a formula of .
homilite
Homilite is a borosilicate mineral belonging to the gadolinite group of minerals with formula .
akaganeite
Akaganeite, also written as the deprecated Akaganéite, is a chloride-containing iron(III) oxide-hydroxide mineral, formed by the weathering of pyrrhotite (Fe1−xS), an iron-deficient sulfide.
brewsterite
Brewsterite is the name of a series of tectosilicate minerals of the zeolite group. Prior to 1997, brewsterite was recognized as a mineral species, but a reclassification in 1997 by the International Mineralogical Association changed it to a series name, with the mineral species being named brewsterite-Sr and brewsterite-Ba. Brewsterite-Sr, the more common of these, is a hydrous strontium and aluminium silicate, . Small amounts of barium is usually present replacing part of the strontium. The appropriate species name depends on the dominant element. The species are visually indistinguishable,
fassaite
Fassaite is a variety of augite with a very low iron content, . It is named after the Fassa Valley, Italy.
tamarugite
Tamarugite (NaAl(SO4)2·6H2O) is a colorless monoclinic sulfate mineral.
thomsenolite
Thomsenolite is a mineral with formula: NaCaAlF6·H2O. It is an alteration product of cryolite.
tsumebite
Tsumebite is a rare phosphate mineral named in 1912 after the locality where it was first found, the Tsumeb mine in Namibia, well known to mineral collectors for the wide range of minerals found there. Tsumebite is a compound phosphate and sulfate of lead and copper, with hydroxyl, formula . There is a similar mineral called arsentsumebite, where the phosphate group is replaced by the arsenate group , giving the formula . Both minerals are members of the brackebuschite group.
kanoite
Kanoite is a light pinkish brown silicate mineral that is found in metamorphic rocks. It is an inosilicate and has a chemical formula of . It is a member of pyroxene group and clinopyroxene subgroup.
phosphosiderite
Phosphosiderite is a rare mineral named for its main components, phosphate and iron. The siderite at the end of phosphosiderite comes from the word "sideros", the Greek word for iron. It was published in 1890, and has been a valid species since pre-IMA. It is an IMA approved mineral which got grandfathered, meaning its name is still believed to refer to an existing species.
nobleite
Nobleite is a rare borate mineral with the chemical formula CaB6O9(OH)2·3H2O. It was discovered in 1961, in Death Valley, California, and is named for Levi F. Noble, a USGS geologist, in honor of his contributions to the geology of the Death Valley region.
mendozite
Mendozite is a sulfate mineral, one of the alum series, with formula NaAl(SO4)2·11H2O. It is a hydrated form of sodium aluminium sulfate (soda alum).
serpierite
Serpierite () is a rare, sky-blue coloured hydrated sulfate mineral, often found as a post-mining product. It is a member of the devilline group, which has members aldridgeite , campigliaite , devilline , kobyashevite , lautenthalite and an unnamed dimorph of devilline. It is the calcium analogue of aldridgeite and it is dimorphous with orthoserpierite .
sussexite
Sussexite is a manganese borate mineral MnBO2(OH). Crystals are monoclinic prismatic and typically fibrous in occurrence. Colour is white, pink, yellowish white with a pearly lustre. It has a Mohs hardness of 3 and a specific gravity of 3.12.
triploidite
Triploidite is an uncommon manganese iron phosphate mineral with formula: . It crystallizes in the monoclinic crystal system and typically occurs as elongated and striated slender prisms which may be columnar to fibrous. Its crystals may be pinkish to yellowish brown or red-orange.
zabuyelite
Zabuyelite is the natural mineral form of lithium carbonate, with a formula Li2CO3. It was discovered in 1987 at Lake Zabuye, Tibet, after which it is named. It forms colorless vitreous monoclinic crystals.
nissonite
Nissonite is a very rare copper phosphate mineral with the formula: Cu2Mg2(PO4)2(OH)2·5H2O. It crystallizes in the monoclinic crystal system typically as crusts, tabular crystals, and diamond-shaped crystals. The color is blue-green. It has a light green streak, a Mohs hardness of 2.5 and a specific gravity of 2.73. Cleavage is {100} distinct.
tschermakite
The endmember hornblende tschermakite () is a calcium-rich monoclinic amphibole mineral. It is frequently synthesized along with its ternary solid solution series members tremolite and cummingtonite so that the thermodynamic properties of its assemblage can be applied to solving other solid solution series from a variety of amphibole minerals.
freieslebenite
Freieslebenite is a sulfosalt mineral composed of antimony, lead, and silver. Sulfosalt minerals are complex sulfide minerals with the formula: AmBnSp. The formula of freieslebenite is AgPbSbS3.
bobfergusonite
Bobfergusonite is a mineral with formula Na2Mn5FeAl(PO4)6. The mineral varies in color from green-brown to red-brown. It was discovered in 1986 in Manitoba, Canada, and named for Robert Bury Ferguson (19202015), a professor of geological sciences at the University of Manitoba. , the mineral has only been found in Canada and Argentina.
keyite
Keyite is a mineral with the chemical formula . The name comes from Charles Locke Key (born 1935), an American mineral dealer who furnished its first specimens.
Keyite is monoclinic-prismatic, meaning its crystal form has three unequal axes, two of which have 90° angles between them and one with an angle less than 90°.
Keyite belongs to the biaxial optical class, meaning it has more than one axis of anisotropy (optic axis), in which light travels with zero birefringence, and three indices of refraction, nα = 1.800, nβ, and nγ = 1.870. Being a very rare cadmium copper arsenate, keyite is only f
xocolatlite
Xocolatlite is a sulfate mineral named for its chocolatey appearance. Discovered in the La Bambolla gold mine of Moctezuma, Sonora, Mexico, Xocolatlite's name is derived from the Nahuatl word xocolatl (literally "bitter water"; a root word of "chocolate"), a drink made from cocoa, water, and chili.
davisite
Davisite is an exceedingly rare mineral of the pyroxene group, with formula CaScAlSiO6. It is the scandium-dominant member. It stands for scandium-analogue of other pyroxene-group members, esseneite, grossmanite and kushiroite. Davisite is one of scarce minerals containing essential scandium.
kegelite
Kegelite is a complex silicate mineral with formula Pb8Al4Si8O20(SO4)2(CO3)4(OH)8.
wodginite
Wodginite is a manganese, tin, tantalum oxide mineral with the chemical formula . It may also include significant amounts of niobium.
boussingaultite
thumb | right | alt=boussingaultite | boussingaultite
Boussingaultite is a rare ammonium magnesium hydrated sulfate mineral of the chemical formula: (NH4)2Mg(SO4)2 · 6 H2O. The formula of boussingaultite is that of Tutton's salts type. It was originally described from geothermal fields in Tuscany, Italy, where it occurs together with its iron analogue mohrite, but is more commonly found on burning coal dumps. The mineral possess monoclinic symmetry and forms clear, often rounded crystals.
niedermayrite
Niedermayrite is a rare hydrated copper cadmium sulfate hydroxide mineral with formula: Cu4Cd(SO4)2(OH)6·4H2O. It crystallizes in the monoclinic system and occurs as encrustations and well formed vitreous blue-green prismatic crystals. It has a specific gravity of 3.36.
gunningite
Gunningite is one of the minerals in the Kieserite group, with the chemical formula . Its name honours Henry Cecil Gunning (1901–1991) of the Geological Survey of Canada and a professor at the University of British Columbia.
nesquehonite
Nesquehonite is a mineral of magnesium carbonate (). It represents the trihydrate of magnesium carbonate, and has the total formula .
It was described in 1890 by F. A. Genth and S. L. Penfield and is named after its type locality of Nesquehoning, Pennsylvania, where it was sampled from a coal mine. Nesquehonite can form from the related pentahydrate Lansfordite by dehydration at room temperature.
cabalzarite
Cabalzarite is a rare arsenate mineral with the chemical formula . It is a member of the tsumcorite group. It crystallizes in the monoclinic system and typically occurs as clusters of crystals or granular aggregates.
searlesite
Searlesite is a sodium borosilicate mineral, with the chemical formula NaBSi2O5(OH)2. It was discovered in 1914 at Searles Lake, California, and was named to honor John W. Searles (16 November 1828 – 7 October 1897), California pioneer, who drilled the well that yielded the first known Searlesite.
yuksporite
Yuksporite is a rare inosilicate mineral with double width, unbranched chains, and the complicated chemical formula .
It contains the relatively rare elements strontium, titanium and niobium, as well as the commoner metallic elements potassium, calcium, sodium and manganese. As with all silicates, it contains groups of linked silicon and oxygen atoms, as well as some associated water molecules.
zincmelanterite
Zincmelanterite is a mineral, a sulfate of zinc, copper and iron with the chemical formula . It is a soft monoclinic yellow green mineral with Mohs hardness of 2 and a specific gravity of 2.02.
berryite
Berryite is a mineral with the formula . It occurs as gray to blue-gray monoclinic prisms. It is opaque and has a metallic luster. It has a Mohs hardness of 3.5 and a specific gravity of 6.7.
zellerite
Zellerite is a uranium mineral, named after its discoverer, geologist Howard Davis Zeller. It has a type locality of the Lucky MC uranium mine in Wyoming, USA. It was approved by the IMA in 1965, but was first published a year after its approval.