Montbrayite, (Au,Ag,Sb,Pb,Bi)<sub>23</sub>(Te,Sb,Pb,Bi)<sub>38</sub>, From the Robb-Montbray Mine, Montbray, QuéBec: Crystal Structure and Revision of the Chemical Formula

Bindi, Luca; Paar, Werner H.; Lepore, Giovanni Orazio

doi:10.3749/canmin.1700095

Cited by 7 publications

(5 citation statements)

References 23 publications

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“…It is a molecular structure and hence it is structurally very different from the well-known gold tellurides (e.g. Bindi et al ., 2018 and references therein). The presence of molecular clusters in the maletoyvayamite structure resembles crystal structures of realgar, AsS, though that structure contains As 4 S 4 molecules (Mullen and Nowacki, 1972) and hence is structurally very different from maletoyvayamite.…”

Section: Structure Descriptionmentioning

confidence: 99%

Maletoyvayamite, Au₃Se₄Te₆, a new mineral from Maletoyvayam deposit, Kamchatka peninsula, Russia

Tolstykh

Tuhý

Vymazalová

et al. 2020

MinMag

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Maletoyvayamite, Au3Se4Te6, is a new mineral discovered in a heavy-mineral concentrate from the Gaching occurrence of the Maletoyvayam deposit, Kamchatka, Russia (60°19′51.87″N, 164°46′25.65″E). It forms anhedral grains (10 to 50 μm in size) and is found in intergrowths with native gold (Au–Ag), Au tellurides (calaverite), unnamed phases (AuSe, Au2TeSe and Au oxide), native tellurium, sulfosalts (tennantite, tetrahedrite, goldfieldite and watanabeite) and supergene tripuhyite. Maletoyvayamite has a good cleavage on {010} and {001}. In plane-polarised light, maletoyvayamite is grey, has strong bireflectance (grey to bluish grey), and strong anisotropy; it exhibits no internal reflections. Reflectance values for maletoyvayamite in air (Rmin,Rmax in %) are: 38.9, 39.1 at 470 nm; 39.3, 39.5 at 546 nm; 39.3, 39.6 at 589 nm; and 39.4, 39.7 at 650 nm. Sixteen electron-microprobe analyses of maletoyvayamite gave an average composition: Au 34.46, Se 16.76, Te 47.23 and S 0.84, total 99.29 wt.%, corresponding to the formula Au2.90(Se3.52S0.44)Σ3.96Te6.14 based on 13 atoms; the average of eleven analyses on synthetic analogue is: Au 34.20, Se 19.68 and Te 45.42, total 99.30 wt.%, corresponding to Au2.90Se4.16Te5.94. The calculated density is 7.98 g/cm3. The mineral is triclinic, space group P1, with a = 8.901(2), b = 9.0451(14), c = 9.265(4) Å, α = 97.66(3), β = 106.70(2), γ = 101.399(14)°, V = 685.9(4) Å3 and Z = 2. The crystal structure of maletoyvayamite represents a unique structure type resembling a molecular structure. There are cube-like [Au6Se8Te12] clusters linked via van der Waals interactions. The structural identity of maletoyvayamite with the synthetic Au3Se4Te6 was confirmed by powder X-ray diffraction and Raman spectroscopy.

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Section: Structure Descriptionmentioning

confidence: 99%

Maletoyvayamite, Au₃Se₄Te₆, a new mineral from Maletoyvayam deposit, Kamchatka peninsula, Russia

Tolstykh

Tuhý

Vymazalová

et al. 2020

MinMag

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“…Montbrayite is rare and usually contains Bi, Pb, Sb, and other elements. [10][11][12][13][14][15][16] Its formula composition is (Au,Ag,Sb,Bi,Pb) 23 (Те,Sb,Bi,Pb) 38 . [16] Maletoyvayamite, a gold chalcogenide with composition Au 3 Te 6 Se 4 , was recently registered as a new mineral.…”

mentioning

confidence: 99%

“…[10][11][12][13][14][15][16] Its formula composition is (Au,Ag,Sb,Bi,Pb) 23 (Те,Sb,Bi,Pb) 38 . [16] Maletoyvayamite, a gold chalcogenide with composition Au 3 Te 6 Se 4 , was recently registered as a new mineral. [17][18][19] It was found at the Maletoyvayam deposit, Kamchatka peninsula (Russia).…”

mentioning

confidence: 99%

Characterization of synthetic and natural gold chalcogenides by electron microprobe analysis, X‐ray powder diffraction, and Raman spectroscopic methods

Palyanova

Beliaeva

Кох

et al. 2022

J Raman Spectroscopy

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Electron microprobe analysis (EMPA), X-ray powder diffraction (XRD), and Raman spectroscopy (RS) were applied to characterize the synthetic gold chalcogenides of the Au-Te-Se-S system and natural analogs from the Gaching deposit (Central Kamchatka, Russia). The EPMA results showed that the synthetic chalcogenides have different Te/Se/S and Au/X (X = Te + Se + S) ratios: AuX 2 , Au 3 X 10 , and AuX. They are similar in composition to natural compoundscalaverite (AuTe 2 ), maletoyvayamite (Au 3 Te 6 Se 4 ), and unnamed minerals AuTe 0.7 Se 0.3 and AuSe 0.7 S 0.3 . It was established that chalcogenides AuX, Au 3 X 10 , and AuX 2 have a specific Raman spectra with characteristic peaks. The position of the peaks and the character of the spectra of the synthetic phases and their natural analogs from the Gaching deposit coincide within the limits of accuracy. Different ratios of chalcogenes Te/Se/S in compounds influence the Raman peak positions. The positions of the peaks for natural compounds AuX differ depending on the predominance of Te (AuTe 0.7 Se 0.3 ) or Se (AuSe 0.7 S 0.3 ). AuSe synthetic phases consist of a mixture of αand β-polymorphs. Raman spectroscopy can be used for the identification of natural gold chalcogenides worldwide, which are difficult to diagnose by other methods due to the microscopic grain sizes and close intergrowths with other ore minerals. The similarity of the Raman spectra upon changing the concentrations of Se and S suggests identical structures and possible isomorphism in the composition range of AuTe 0.

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“…By analogy with the montbrayite structure (Bindi et al ., 2018), where the Au–Sb substitution was observed, the occupancy of the Au position was also refined (Au versus vacancy). The refinement indicated a fully occupied Au position.…”

Section: X-ray Crystallographymentioning

confidence: 99%

“…Aurostibite shows a three-dimensional network composed of corner-sharing [AuSb 6 ] octahedra (Furuseth et al , 1965) whereas pampaloite shows a layered structure. In the montbrayite structure (Bindi et al ., 2018), the [AuTe 6 ] octahedra form edge-sharing octahedral chains along [101], generating empty spaces with Te–Te contacts (from 2.83 to 2.90 Å).…”

Section: X-ray Crystallographymentioning

confidence: 99%

Pampaloite, AuSbTe, a new mineral from Pampalo gold mine, Finland

Vymazalová

Kojonen²,

Laufek

et al. 2018

MinMag

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Pampaloite, AuSbTe, is a new mineral discovered in the Pampalo gold mine, 65 km east of Joensuu, Finland. It forms anhedral grains (up to ~20 μm) intergrown with gold, frohbergite and altaite. Pampaloite is brittle and has a metallic lustre. Values of VHN25 lie between 245 and 295 kg/mm2, with a mean value of 276 kg/mm2, corresponding to a Mohs hardness of ~4–5 (measured on synthetic material). In plane-polarised light, pampaloite is white with medium to strong bireflectance, weak reflectance pleochroism from slightly pinkish brown to slightly bluish white (only visible in grains of synthetic material containing multiple orientations), and strong anisotropy, with blue to light brown rotation tints; it exhibits no internal reflections. Reflectance values of pampaloite in air (R1, R2 in %) are: 60.0, 62.5 at 470 nm, 62.5, 64.8 at 546 nm, 63.2, 65.6 at 589 nm and 63.7, 66.0 at 650 nm. Ten electron-microprobe analyses of natural pampaloite give an average composition: Au 44.13, Sb 27.44 and Te 28.74, total 100.31 wt.%, corresponding to the empirical formula Au1.00Sb1.00Te1.00 based on 3 atoms; the average of eleven analyses on synthetic pampaloite is: Au 44.03, Sb 27.26, and Te 29.08, total 100.38 wt.%, corresponding to Au0.99Sb1.00Te1.01. The density, calculated on the basis of the empirical formula, is 9.33 g/cm3.The mineral is monoclinic, space group C2/c, with a = 11.947(3), b = 4.481(1) Å, c = 12.335(3) Å, β = 105.83(2)°, V = 635.3(3) Å3 and Z = 8. The crystal structure was solved and refined from the single-crystal X-ray-diffraction data of synthetic AuSbTe. The pampaloite crystal structure can be considered as a monoclinic derivative of the CdI2 structure composed of [AuTe3Sb3] octahedra. The strongest lines in the powder X-ray diffraction pattern of synthetic pampaloite [d in Å (I) (hkl)] are: 4.846(24)($\bar{2}$02), 3.825(18)(111), 2.978(100)($\bar{3}$11), 2.968(50)(004), 2.242(25)(020), 2.144(55)(313), 2.063(33)($\bar{3}$15) and 1.789(18)(024).

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Montbrayite, (Au,Ag,Sb,Pb,Bi)₂₃(Te,Sb,Pb,Bi)₃₈, From the Robb-Montbray Mine, Montbray, QuéBec: Crystal Structure and Revision of the Chemical Formula

Cited by 7 publications

References 23 publications

Maletoyvayamite, Au₃Se₄Te₆, a new mineral from Maletoyvayam deposit, Kamchatka peninsula, Russia

Maletoyvayamite, Au₃Se₄Te₆, a new mineral from Maletoyvayam deposit, Kamchatka peninsula, Russia

Characterization of synthetic and natural gold chalcogenides by electron microprobe analysis, X‐ray powder diffraction, and Raman spectroscopic methods

Pampaloite, AuSbTe, a new mineral from Pampalo gold mine, Finland

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Montbrayite, (Au,Ag,Sb,Pb,Bi)23(Te,Sb,Pb,Bi)38, From the Robb-Montbray Mine, Montbray, QuéBec: Crystal Structure and Revision of the Chemical Formula

Cited by 7 publications

References 23 publications

Maletoyvayamite, Au3Se4Te6, a new mineral from Maletoyvayam deposit, Kamchatka peninsula, Russia

Maletoyvayamite, Au3Se4Te6, a new mineral from Maletoyvayam deposit, Kamchatka peninsula, Russia

Characterization of synthetic and natural gold chalcogenides by electron microprobe analysis, X‐ray powder diffraction, and Raman spectroscopic methods

Pampaloite, AuSbTe, a new mineral from Pampalo gold mine, Finland

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Montbrayite, (Au,Ag,Sb,Pb,Bi)₂₃(Te,Sb,Pb,Bi)₃₈, From the Robb-Montbray Mine, Montbray, QuéBec: Crystal Structure and Revision of the Chemical Formula

Maletoyvayamite, Au₃Se₄Te₆, a new mineral from Maletoyvayam deposit, Kamchatka peninsula, Russia

Maletoyvayamite, Au₃Se₄Te₆, a new mineral from Maletoyvayam deposit, Kamchatka peninsula, Russia