Djurleite

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Djurleite
Djurleite 04.jpg
Djurleite pseudomorph after pyrite from New Mexico, specimen size 2.4 cm
General
CategoryCopper sulfide
Formula
(repeating unit)
Cu31S16
IMA symbol Dju [1]
Strunz classification 2.BA.05b
Dana classification2.4.7.2
Crystal system Monoclinic
Crystal class Prismatic (2/m)
(same H-M symbol)
Space group P21/n
Unit cell a = 26.897, b = 15.745
c = 13.565 [Å]; β = 90.13°; Z = 8
Identification
Formula mass 2483 g/mol
ColorGrey, blue-black or black
Crystal habit Crystals are short prismatic and thick tabular, also massive and compact
Twinning Pseudohexagonal twins are common, twin axis [100]. [2]
Cleavage None
Fracture Conchoidal
Tenacity Brittle
Mohs scale hardness2+12 to 3
Luster Submetallic to metallic
Streak Black
Diaphaneity Opaque
Specific gravity 5.63 [3]
References [4] [5] [6] [7]

Djurleite is a copper sulfide mineral of secondary origin with formula Cu31S16 that crystallizes with monoclinic-prismatic symmetry. It is typically massive in form, but does at times develop thin tabular to prismatic crystals. It occurs with other supergene minerals such as chalcocite, covellite and digenite in the enriched zone of copper orebodies. It is a member of the chalcocite group, and very similar to chalcocite, Cu2S, in its composition and properties, but the two minerals can be distinguished from each other by x-ray powder diffraction. [8] Intergrowths and transformations between djurleite, digenite and chalcocite are common. [2] Many of the reported associations of digenite and djurleite, however, identified by powder diffraction, could be anilite and djurleite, as anilite transforms to digenite during grinding. [5]

Contents

Djurleite was named for the Swedish chemist Seved Djurle (1928–2000), from the University of Uppsala, Sweden, who first synthesized the mineral in 1958, prior to its discovery in nature. The natural material was first described in 1962 by E H Roseboom Jr, of the US Geological Survey, from occurrences at the type locality, Barranca del Cobre, Chihuahua, Mexico. [8]

The chalcocite group

The chalcocite group is a group of closely related copper sulfides, with the formulae: [9]

Unit cell

Djurleite has a monoclinic structure with a large unit cell containing 248 copper and 128 sulfur atoms. [10] The formula is Cu31S16, molar mass 2483 g, and there are 8 formula units per unit cell (Z = 8).

The crystal class is 2/m, meaning the structure has an axis of twofold rotational symmetry perpendicular to a mirror plane. The space group is P21/c, and the unit cell parameters are a = 26.897  Å, b = 15.745 Å, c = 13.565 Å and β = 90.13°. The structure is based on hexagonal closest packing of sulfur atoms with a monoclinic space group. [11]

Physical properties

Crystals are short prismatic and thick tabular, but the mineral usually occurs in a massive and compact form. There is no cleavage. Pseudohexagonal twins are common, with crystal blocks rotated around the a crystal axis, which is normal to the close-packed layers, by multiples of 60°. [2] Djurleite is brittle, with a conchoidal (shell-like) fracture. It is a soft mineral, with hardness 2+12 to 3, a little less than that of calcite. The specific gravity, 5.63, is high, due to the copper content, djurleite is denser than the copper-iron sulfide bornite, but not as dense as the iron-arsenic sulfide arsenopyrite.

Optical properties

Djurleite is grey, blue-black or black, with a black streak and a submetallic to metallic luster. It is an opaque mineral, so refractive indices are not defined. The reflectivity (the percentage of incident energy which is reflected from a surface) for light of wavelength 540  nm varies between 29.6 and 30.2, and is slightly dependent on the direction of the incident light, that is to say, the mineral is weakly anisotropic. [4] [6] [7]

Environment

Djurleite with quartz and pyrite from Butte, Montana (size: 9.0 x 6.2 x 4.0 cm) Djurleite-Quartz-Pyrite-261713.jpg
Djurleite with quartz and pyrite from Butte, Montana (size: 9.0 x 6.2 x 4.0 cm)

Djurleite is a widely distributed but little known ore mineral of copper, found in the secondary enrichment zones of copper deposits, associated with other secondary copper sulfides digenite, chalcocite, bornite, chalcopyrite and anilite with pyrite. [7]

Occurrence

The type locality is Barranca de Cobre, Chihuahua, Mexico, and the type material is conserved at the Royal Ontario Museum, Toronto, Canada, M25369, and at the National Museum of Natural History, Washington, DC, US. [7]

Related Research Articles

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Germanite is a rare copper iron germanium sulfide mineral, Cu26Fe4Ge4S32. It was first discovered in 1922, and named for its germanium content. It is only a minor source of this important semiconductor element, which is mainly derived from the processing of the zinc sulfide mineral sphalerite. Germanite contains gallium, zinc, molybdenum, arsenic, and vanadium as impurities.

<span class="mw-page-title-main">Bornite</span> Sulfide mineral

Bornite, also known as peacock ore, is a sulfide mineral with chemical composition Cu5FeS4 that crystallizes in the orthorhombic system (pseudo-cubic).

<span class="mw-page-title-main">Chalcocite</span> Sulfide mineral

Chalcocite, copper(I) sulfide (Cu2S), is an important copper ore mineral. It is opaque and dark gray to black, with a metallic luster. It has a hardness of 2.5–3 on the Mohs scale. It is a sulfide with a monoclinic crystal system.

<span class="mw-page-title-main">Covellite</span> Sulfide mineral

Covellite is a rare copper sulfide mineral with the formula CuS. This indigo blue mineral is commonly a secondary mineral in limited abundance and although it is not an important ore of copper itself, it is well known to mineral collectors.

<span class="mw-page-title-main">Linarite</span> Copper lead sulfate hydroxide mineral

Linarite is a somewhat rare, crystalline mineral that is known among mineral collectors for its unusually intense, pure blue color. It is formed by the oxidation of galena and chalcopyrite and other copper sulfides. It is a combined copper lead sulfate hydroxide with formula PbCuSO4(OH)2. Linarite occurs as monoclinic prismatic to tabular crystals and irregular masses. It is easily confused with azurite, but does not react with dilute hydrochloric acid as azurite does. It has a Mohs hardness of 2.5 and a specific gravity of 5.3 - 5.5.

<span class="mw-page-title-main">Enargite</span> Sulfosalt mineral

Enargite is a copper arsenic sulfosalt mineral with formula Cu3AsS4. It takes its name from the Greek word enarge, "distinct". Enargite is a steel gray, blackish gray, to violet black mineral with metallic luster. It forms slender orthorhombic prisms as well as massive aggregates. It has a hardness of 3 and a specific gravity of 4.45.

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

Fukuchilite, Cu
3
FeS
8
, is a copper iron sulfide named after the Japanese mineralogist Nobuyo Fukuchi (1877–1934), that occurs in ore bodies of gypsum-anhydrite at the intersection points of small masses of barite, covellite, gypsum and pyrite, and is mostly found in the Hanawa mine in the Akita prefecture of Honshū, Japan where it was first discovered in 1969. It occurs in masses within the third geologic unit of the Kuroko type deposits within the mine.

<span class="mw-page-title-main">Digenite</span> Copper sulfide mineral

Digenite is a copper sulfide mineral with formula: Cu9S5. Digenite is a black to dark blue opaque mineral that crystallizes with a trigonal - hexagonal scalenohedral structure. In habit it is usually massive, but does often show pseudo-cubic forms. It has poor to indistinct cleavage and a brittle fracture. It has a Mohs hardness of 2.5 to 3 and a specific gravity of 5.6. It is found in copper sulfide deposits of both primary and supergene occurrences. It is typically associated with and often intergrown with chalcocite, covellite, djurleite, bornite, chalcopyrite and pyrite. The type locality is Sangerhausen, Thuringia, Germany, in copper slate deposits.

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

Carrollite, CuCo2S4, is a sulfide of copper and cobalt, often with substantial substitution of nickel for the metal ions, and a member of the linnaeite group. It is named after the type locality in Carroll County, Maryland, US, at the Patapsco mine, Sykesville.

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<span class="mw-page-title-main">Copper(I) sulfide</span> Chemical compound

Copper(I) sulfide is a copper sulfide, a chemical compound of copper and sulfur. It has the chemical compound Cu2S. It is found in nature as the mineral chalcocite. It has a narrow range of stoichiometry ranging from Cu1.997S to Cu2.000S. Samples are typically black.

Fletcherite is a rare thiospinel sulfide mineral with formula Cu(Ni,Co)2S4. It is an opaque metallic steel gray mineral which crystallizes in the cubic crystal system. It is a member of the linnaeite group.

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

Alacránite (As8S9) is an arsenic sulfide mineral first discovered in the Uzon caldera, Kamchatka, Russia. It was named for its occurrence in the Alacrán silver/arsenic/antimony mine. Pampa Larga, Chile. It is generally more rare than realgar and orpiment. Its origin is hydrothermal. It occurs as subhedral to euhedral tabular orange to pale gray crystals that are transparent to translucent. It has a yellow-orange streak with a hardness of 1.5. It crystallizes in the monoclinic crystal system. It occurs with realgar and uzonite as flattened and prismatic grains up to 0.5 mm across.

<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">Plancheite</span>

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

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Xilingolite is a lead sulfide mineral with formula Pb3Bi2S6. It has a hardness of 3, a metallic luster, and usually exhibits a lead-grey color. It is a dimorph of lillianite, exhibiting increased Pb-Bi order and decreased symmetry.

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

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

Oosterboschite is a rare selenide mineral with the formula (Pd,Cu)7Se5. It crystallises in the orthorhombic crystal system. It has a creamy yellow colour and a Moh's hardness of 5. It is often found as grains with no clear shape. The crystals are opaque and often no bigger than 0.4 mm.

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 Pósfai, M. & Buseck, P. R. (1994): Djurleite, digenite, and chalcocite: Intergrowths and transformations. American Mineralogist, 79, 308-315
  3. Fleischer M (1963) New mineral names, American Mineralogist 48, 215
  4. 1 2 Gaines et al (1997) Dana’s New Mineralogy Eighth Edition, Wiley
  5. 1 2 Mindat.org
  6. 1 2 Webmineral data
  7. 1 2 3 4 Handbook of Mineralogy
  8. 1 2 Roseboom, E.H. (1962) Djurleite, Cu1.96S, a new mineral. American Mineralogist: 47: 1181-1184.
  9. "IMA Mineral List with Database of Mineral Properties".
  10. H. T. Evans "Djurleite (Cu1.94S) and Low Chalcocite (Cu2S): New Crystal Structure Studies" Science 203 (1979) 356
  11. Klein et al (1993) Manual of Mineralogy 21st Edition, Wiley