Coyoteite

Last updated
Coyoteite
General
Category Sulfide mineral
Formula
(repeating unit)
(NaFe3S5·2H2O)
IMA symbol Coy [1]
Strunz classification 2.FD.25
Dana classification02.14.06.01
Crystal system Triclinic
Unknown space group
Identification
Colorblack
Crystal habit Irregular grains - occurs as splotchy, anhedral crystals forming inclusions in other minerals
Cleavage {111} Perfect
Mohs scale hardness1-1.5
Luster Metallic
Streak black
Diaphaneity Opaque
Specific gravity 2.5 - 2.62 measured; 2.879 calculated
Pleochroism Faint, from gray to pink
Other characteristicsModerately magnetic
References [2] [3] [4] [5]

Coyoteite is a hydrated sodium iron sulfide mineral. The mineral was named coyoteite after Coyote Peak near Orick, California, where it was discovered (along with another rare mineral, orickite). [2]

Contents

This mineral is unstable under normal atmospheric conditions, making it rare at the surface. The mineral was first described in a petrographic study of a sample of a mafic diatreme at Coyote Peak. The largest piece of coyoteite found on that specimen has the dimensions of 0.2 × 0.4 mm. [2]

Chemical composition and properties

The chemical formula of the mineral is NaFe3S5·2H2O. [2] It was obtained by the analysis of five grains using the 10-kV EMX-SM electron microprobe. [2] The total concentration of detected elements was less than 100% (90.7 weight percent). Qualitative analyses and TAP crystal were used to find the missing 9.31%. The results confirmed the missing elements to be hydrogen and oxygen, which are undetectable by the electron microprobe. [2] It was unclear however whether the hydrogen and oxygen are in the form of water or a hydroxide. [2]

The mineral is insoluble in cold acids, such as HCl, but dissolves upon heating. [2]

Physical and optical properties

Coyoteite is black in color and is streaked with opaque metallic luster in fragmental samples. [2] The mineral has perfect cleavage on the {111} planes and shows a unique chevron pattern because of the diametrical arrangement of these crystallographically equivalent cleavage planes. [2] The measured density is 2.5 to 2.6 g/cm3 and the calculated one is 2.879 g/cm3. This significant density difference is because of the presence of epoxy between the cleavage planes. [2] The hardness is 1.5 on Mohs scale and is comparable to that of erdite (NaFeS2·2H2O) which has a similar chemical composition. Coyoteite is moderately magnetic. [2] On the polished thin section, coyoteite is pale brownish to gray, with pink tint. It shows low pleochroism, from gray to pink. In reverse, it shows large optical anisotropy, from gray to dull golden orange. [2]

Crystallography

The X-ray precession image classifies the coyoteite crystal system as triclinic. The crystal belongs to P1 or P1 space group and to 1 or 1 point group. Imaging shows that coyoteite has poor crystal quality. [2] The X-ray diffraction pattern suggests the following value for the crystallographic axes a = 7.409 Å, b = 9.881 Å, c = 6.441 Å; α = 100° 25’, β = 104° 37’ and γ = 81° 29’; the unit cell volume is V = 446.2 Å3. [2]

Possible atomic structure

Scarcity of coyoteite hinders attempts to determine its atomic structure. It is unknown whether the oxygen and the hydrogen are present in the mineral as H2O molecules or OH anions. However, because of the softness and the lamellar cleavage in the mineral, coyoteite structure might be close to that of valleriite, 4(Fe,Cu)S•3(Mg,Al)(OH)
2
. Valleriite is a layered mineral, it consists of layers of (Mg0.68Al0.32(OH)2) and layers of (Fe0.07Cu0.93S2). [4]

Geologic occurrence

Coyoteite has been found only in the mafic alkalic diatreme at the Coyote Peak near Orick, Humboldt County, California, US. [2] [5] It is formed in pegmatitic clots associated with some rare iron sulfide minerals, such as erdite, bartonite and djerfisherite, as well as with common minerals pyrrhotite and magnetite. [5]

Related Research Articles

<span class="mw-page-title-main">Mineral</span> Crystalline chemical element or compound formed by geologic processes

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

<span class="mw-page-title-main">Hornblende</span> Complex inosilicate series of minerals

Hornblende is a complex inosilicate series of minerals. It is not a recognized mineral in its own right, but the name is used as a general or field term, to refer to a dark amphibole. Hornblende minerals are common in igneous and metamorphic rocks.

<span class="mw-page-title-main">Amphibole</span> Group of inosilicate minerals

Amphibole is a group of inosilicate minerals, forming prism or needlelike crystals, composed of double chain SiO
4
tetrahedra, linked at the vertices and generally containing ions of iron and/or magnesium in their structures. Its IMA symbol is Amp. Amphiboles can be green, black, colorless, white, yellow, blue, or brown. The International Mineralogical Association currently classifies amphiboles as a mineral supergroup, within which are two groups and several subgroups.

<span class="mw-page-title-main">Anhydrite</span> Mineral, anhydrous calcium sulfate

Anhydrite, or anhydrous calcium sulfate, is a mineral with the chemical formula CaSO4. It is in the orthorhombic crystal system, with three directions of perfect cleavage parallel to the three planes of symmetry. It is not isomorphous with the orthorhombic barium (baryte) and strontium (celestine) sulfates, as might be expected from the chemical formulas. Distinctly developed crystals are somewhat rare, the mineral usually presenting the form of cleavage masses. The Mohs hardness is 3.5, and the specific gravity is 2.9. The color is white, sometimes greyish, bluish, or purple. On the best developed of the three cleavages, the lustre is pearly; on other surfaces it is glassy. When exposed to water, anhydrite readily transforms to the more commonly occurring gypsum, (CaSO4·2H2O) by the absorption of water. This transformation is reversible, with gypsum or calcium sulfate hemihydrate forming anhydrite by heating to around 200 °C (400 °F) under normal atmospheric conditions. Anhydrite is commonly associated with calcite, halite, and sulfides such as galena, chalcopyrite, molybdenite, and pyrite in vein deposits.

<span class="mw-page-title-main">Leadhillite</span> Lead sulfate carbonate hydroxide mineral

Leadhillite is a lead sulfate carbonate hydroxide mineral, often associated with anglesite. It has the formula Pb4SO4(CO3)2(OH)2. Leadhillite crystallises in the monoclinic system, but develops pseudo-hexagonal forms due to crystal twinning. It forms transparent to translucent variably coloured crystals with an adamantine lustre. It is quite soft with a Mohs hardness of 2.5 and a relatively high specific gravity of 6.26 to 6.55.

Geigerite is a mineral, a complex hydrous manganese arsenate with formula: Mn5(AsO3OH)2(AsO4)2·10H2O. It forms triclinic pinacoidal, vitreous, colorless to red to brown crystals. It has a Mohs hardness of 3 and a specific gravity of 3.05.

<span class="mw-page-title-main">Campigliaite</span>

Campigliaite is a copper and manganese sulfate mineral with a chemical formula of Cu4Mn(SO4)2(OH)6·4H2O. It has a chemical formula and also a crystal structure similar to niedermayrite, with Cd(II) cation replacing by Mn(II). The formation of campigliaite is related to the oxidation of sulfide minerals to form sulfate solutions with ilvaite associated with the presence of manganese. Campigliaite is a rare secondary mineral formed when metallic sulfide skarn deposits are oxidized. While there are several related associations, there is no abundant source for this mineral due to its rare process of formation. Based on its crystallographic data and chemical formula, campigliaite is placed in the devillite group and considered the manganese analogue of devillite. Campigliaite belongs to the copper oxysalt minerals as well followed by the subgroup M=M-T sheets. The infinite sheet structures that campigliaite has are characterized by strongly bonded polyhedral sheets, which are linked in the third dimension by weaker hydrogen bonds.

<span class="mw-page-title-main">Bergenite</span>

Bergenite is a rare uranyl phosphate of the more specific phosphuranylite group. The phosphuranylite-type sheet in bergenite is a new isomer of the group, with the uranyl phosphate tetrahedra varying in an up-up-down, same-same-opposite (uuduudSSOSSO) orientation. All bergenite samples have been found in old mine dump sites. Uranyl minerals are a large constituent of uranium deposits.

Clearcreekite is a carbonate mineral, polymorphous with peterbaylissite. The chemical formula of clearcreekite is Hg1+3CO3(OH)∙2H2O. It has a pale greenish yellow color and streak with tabular subhedral crystals and good cleavage on {001}. It is transparent with vitreous luster and uneven fracture. Its density (calculated from the idealized formula) is 6.96 g/cm3. The mineral is monoclinic with the space group P2/c. Clearcreekite is an extremely rare mineral from the Clear Creek mercury mine, New Idria district, San Benito County, California. It was probably formed after the alteration of other mercury minerals such as cinnabar. The mineral is named after the locality where it was found.

<span class="mw-page-title-main">Cornubite</span> Copper arsenate mineral

Cornubite is a rare secondary copper arsenate mineral with formula: Cu5(AsO4)2(OH)4. It was first described for its discovery in 1958 in Wheal Carpenter, Gwinear, Cornwall, England, UK. The name is from Cornubia, the medieval Latin name for Cornwall. It is a dimorph of Cornwallite, and the arsenic analogue of pseudomalachite.

<span class="mw-page-title-main">Warikahnite</span> Rare zinc arsenate mineral

Warikahnite is a rare zinc arsenate mineral of the triclinic crystal system with Hermann- Mauguin notation 1, belonging to the space group P1. It occurs in the Tsumeb mine in Namibia on corroded tennantite in the second oxidation zone under hydrothermal conditions in a dolomite-hosted polymetallic ore deposit. It is associated with adamite, stranskiite, koritnigite, claudetite, tsumcorite, and ludlockite. The origin of discovery was in a dolomite ore formation within an oxidized hydrothermal zone, in the E9 pillar, 31st level of the Tsumeb Mine in Namibia, Southwest Africa. It has also been found at Lavrion, Greece and Plaka, Greece as microscopic white needles.

<span class="mw-page-title-main">Hidalgoite</span> Mineral of the beudantite group

Hidalgoite, PbAl3(AsO4)(SO4)(OH)4, is a rare member of the beudantite group and is usually classified as part of the alunite family. It was named after the place where it was first discovered, the Zimapán mining district, Hidalgo, Mexico. At Hidalgo where it was initially discovered, it was found as dense white masses in alternating dikes of quartz latite and quartz monzonite alongside other secondary minerals such as sphalerite, arsenopyrite, cerussite and trace amounts of angelsite and alamosite, it was then rediscovered at other locations such as Australia where it occurs on oxidized shear zones above greywacke shales especially on the anticline prospects of the area, and on fine grained quartz-spessartine rocks in Broken Hill, Australia. Hidalgoite specimens are usually associated with copper minerals, clay minerals, iron oxides and polymetallic sulfides in occurrence.

<span class="mw-page-title-main">Gordaite</span>

Gordaite is a sulfate mineral composed primarily of hydrous zinc sodium sulfate chloride hydroxide with formula: NaZn4(SO4)(OH)6Cl·6H2O. It was named for the discovery location in the Sierra Gorda district of Chile. Gordaite forms as tabular trigonal crystals.

<span class="mw-page-title-main">Köttigite</span>

Köttigite is a rare hydrated zinc arsenate which was discovered in 1849 and named by James Dwight Dana in 1850 in honour of Otto Friedrich Köttig (1824–1892), a German chemist from Schneeberg, Saxony, who made the first chemical analysis of the mineral. It has the formula Zn3(AsO4)2·8H2O and it is a dimorph of metaköttigite, which means that the two minerals have the same formula, but a different structure: köttigite is monoclinic and metaköttigite is triclinic. There are several minerals with similar formulae but with other cations in place of the zinc. Iron forms parasymplesite Fe2+3(AsO4)2·8H2O; cobalt forms the distinctively coloured pinkish purple mineral erythrite Co3(AsO4)2·8H2O and nickel forms annabergite Ni3(AsO4)2·8H2O. Köttigite forms series with all three of these minerals and they are all members of the vivianite group.

<span class="mw-page-title-main">Mammothite</span>

Mammothite is a mineral found in the Mammoth mine in Tiger, Arizona and also in Laurium, Attika, Greece. This mineral was named in 1985 by Donald R. Peacor, Pete J. Dunn, G. Schnorrer-Köhler, and Richard A. Bideaux, for the Mammoth vein (one of the two main veins in the mine) and the town of Mammoth, Arizona, which was named for the mine. The mammothite that is found in Arizona exist as euhedral crystals imbedded in micro granular, white colored anglesite with a saccharoidal texture. The associated minerals include phosgenite, wulfenite, leadhillite and caledonite. In Greece, the mammothite exists as small euhedral crystals and also as microscopic rock cavities lined with projecting crystals within the slags. The associated minerals here are cerussite, phosgenite and matlockite. The ideal chemical formula for mammothite is Pb6Cu4AlSb5+O2(OH)16Cl4(SO4)2.

Lahnsteinite is a basic sulfate mineral first discovered in the Friedrichssegen Mine, Germany in a goethite cavity. Though found in goethite, the crystals of Lahnsteinite are few millimeters in size, and are tabular shaped. Lahnsteinite was the first mineral discovered in the Lahn Valley deposits. The empirical formula for lahnsteinite is (Zn3.3,Fe0.27,Cu0.11)3.91(S0.98O4)(OH)5*3H2.10O.

<span class="mw-page-title-main">Zigrasite</span>

Zigrasite is a phosphate mineral with the chemical formula of MgZr(PO4)2(H2O)4. Zigrasite was discovered and is only known to occur in the Dunton Quarry at Oxford County, Maine. Zigrasite was specifically found in the giant 1972 gem tourmaline-bearing pocket at the Dunton Quarry. Zigrasite is named after James Zigras who originally discovered and brought the mineral to attention.

Lemanskiite is a mineral that was first discovered in a mine at Abundancia mine, El Guanaco mining district, Chile, with the ideal formula of NaCaCu5(AsO4)4Cl•3H2O. Originally, this mineral was discovered as being dimorphus with lavendulan, but in 2018 it was revised to only have 3 water molecules. Lemanskiite typically occurs as rosette-shaped aggregates of thin lamellar or needle-shaped aggregates, such as lammerite. Lemanskiite is dark sky blue with a light blue streak, it is brittle with an excellent cleavage plane. It was found on a dumping site in the abandoned Abundancia mine, El Guanaco mining district, Region II, Antofagasta Province, Chile The new mineral has been named after Chester S. Lemanski, Jr. This mineral and name were then approved by the Commission on New Minerals and Mineral Names of the International Mineralogical Association.

Cattiite is a phosphate mineral. The mineral was first found in a veins of dolomite carbonatites veins at the bottom of the Zhelezny (Iron) Mine in the Kovdor massif, Kola Peninsula, Russia. Cattiite was tentatively identified as Mg3(PO4)2•22H2O, which as a high hydrate magnesium orthophosphate. Later structural studies, revealed the existence of two polytypes named Mg3(PO4)2•22H2O-1A1 and Mg3(PO4)2•22H2O-1A2.

Hexahydroborite is a mineral composed of calcium, boron, oxygen, and hydrogen, with formula CaB2H12O6, more precisely [Ca2+]([B(OH4)])2·2H2O.

References

  1. Warr, L.N. (2021). "IMA–CNMNC approved mineral symbols". Mineralogical Magazine. 85 (3): 291–320. Bibcode:2021MinM...85..291W. doi: 10.1180/mgm.2021.43 . S2CID   235729616.
  2. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Erd, Richard C.; Czamanske, Gerald K. (1983). "Orickite and coyoteite, two new sulfide minerals from Coyote Peak, HunboldtCountry, California" (PDF). American Mineralogist. 68: 245–254.
  3. V. Pekov, A.A. Agakhanov (2007). Thallium-Rich Murunskite from the Lovozero Pluton, Kola Peninsula, and Partitioning of Alkali Metals and Thallium between Sulfide Minerals. Vol. 4. Zapiski Rossiskogo Mineralogicheskogo Obshchestva. pp. 74–78.
  4. 1 2 Evans, J.R.; Allmann, R. (1968). The crystal structure and crystal chemistry of Valleriite. Vol. 127. Zeitschrift flir Kristallographie, Bd. pp. 73–93.
  5. 1 2 3 Anthony, J. W., Bedeaux, R., Bladh, K. and Nicholas, M. (1990). Handbook of Mineralogy (PDF). Vol. 1. Mineral Data Publishing (Republished by the Mineralogical Society of America).{{cite book}}: CS1 maint: multiple names: authors list (link)