Prossima pubblicazione.
Referenza:
▪ Kampf; A.R., Housley, R.M., Rossman, G.R. (2018): Pararaisaite, the Dimorph of Raisaite, from the North Star Mine, Tintic, Utah, Usa. Canadian Mineralogist, 56, (in press).
Abstract:
Pararaisaite, Cu2+Mg[Te6+O4(OH)2]·6H2O, is a new mineral from the North Star mine, Tintic district, Juab County, Utah, USA. It is an oxidation-zone mineral occuring in vugs in a matrix of massive quartz with embedded crystals of baryte and goldfieldite. Crystals are deep blue, striated prisms up to 0.4 mm in length, elongated on [010] and exhibiting the forms {100}, {001}, {102}, ..., and {114}. The mineral is transparent with vitreous luster, white streak, Mohs hardness 2½, brittle tenacity, splintery fracture, and two cleavages: perfect on {001} and good on {100}. The measured density is 2.85(2) g/cm3. Pararaisaite is biaxial (+) with α = 1.600(2), β = 1.616(2), γ = 1.713(3) (white light); 2V = 47(1)°; slight r > v dispersion; orientation Z = b, X ≈ a, Y ≈ c; and pleochroism X very pale purple, Y purple, Z blue green (X << Z < Y). The Raman spectrum is consistent with the presence of tellurate, OH, and H2O. Electron-microprobe analyses gave the empirical formula (Mg1.10Cu0.93Te0.96Sb0.01)Σ3O12H14.12. The mineral is monoclinic, space group P21/c, with a 9.6838(5), b 5.75175(19), c 17.6339(12) Å, β 90.553(6)°, V 982.14(9) Å3, and Z = 4. The five strongest X-ray powder diffraction lines are [dobs Å(I)(hkl)]: 8.77(100)(002), 4.824(71)(200,111), ..., 2.419(50)(400,024), and .... Pararaisaite is dimorphous with raisaite. The structure contains straight edge-sharing chains of alternating Cu2+O4(OH)2 and Te6+O4(OH)2 octahedra. The chains link to one another via shared octahedral corners to form [Cu2+Te6+O4(OH)2]2– sheets. Interlayer Mg(H2O)6 octahedra link the sheets via hydrogen bonds.
IMA 2017-110 = pararaisaite
- Marco E. Ciriotti
- Messaggi: 26199
- Iscritto il: ven 25 giu, 2004 11:31
- Località: via San Pietro, 55 I-10073 Devesi/Cirié TO - Italy
- Contatta:
IMA 2017-110 = pararaisaite
Marco E. Ciriotti
«Things are interesting only in so far as they relate themselves to other things»
«Things are interesting only in so far as they relate themselves to other things»
- Marco E. Ciriotti
- Messaggi: 26199
- Iscritto il: ven 25 giu, 2004 11:31
- Località: via San Pietro, 55 I-10073 Devesi/Cirié TO - Italy
- Contatta:
Re: IMA 2017-110 = pararaisaite
25 sono i minerali che contengono Cu2+ e Te6+.
Interessante notare che, così come raisaite e pararaisaite [Cu2+Mg[Te6+O4(OH)2]∙6H2O], soltanto millsite e teinite [Cu2+[Te4+O3]·2H2O] presentano analogo dimorfismo.
Pertanto sia per Cu2+ e Te6+ quanto per Cu2+ e Te4+, sinora, si registra un solo caso di dimorfismo.
Interessante notare che, così come raisaite e pararaisaite [Cu2+Mg[Te6+O4(OH)2]∙6H2O], soltanto millsite e teinite [Cu2+[Te4+O3]·2H2O] presentano analogo dimorfismo.
Pertanto sia per Cu2+ e Te6+ quanto per Cu2+ e Te4+, sinora, si registra un solo caso di dimorfismo.
Marco E. Ciriotti
«Things are interesting only in so far as they relate themselves to other things»
«Things are interesting only in so far as they relate themselves to other things»
- Marco E. Ciriotti
- Messaggi: 26199
- Iscritto il: ven 25 giu, 2004 11:31
- Località: via San Pietro, 55 I-10073 Devesi/Cirié TO - Italy
- Contatta:
Re: IMA 2017-110 = pararaisaite
Pubblicazione effettuata.
Referenza:
▪ Kampf; A.R., Housley, R.M., Rossman, G.R. (2018): Pararaisaite, the Dimorph of Raisaite, from the North Star Mine, Tintic, Utah, Usa. Canadian Mineralogist, 56, 811-820.
Abstract:
Pararaisaite, Cu2+Mg[Te6+O4(OH)2]·6H2O, is a new mineral from the North Star mine, Tintic district, Juab County, Utah, USA. It is an oxidation-zone mineral occuring in vugs in a matrix of massive quartz with embedded crystals of baryte and goldfieldite. Crystals are deep blue, striated prisms up to 0.4 mm in length, elongated on [010] and exhibiting the forms {100}, {001}, {102}, {10-2}, and {114}. The mineral is transparent with vitreous luster, white streak, Mohs hardness 2½, brittle tenacity, splintery fracture, and two cleavages: perfect on {001} and good on {100}. The measured density is 2.85(2) g/cm3. Pararaisaite is biaxial (+) with α = 1.600(2), β = 1.616(2), γ = 1.713(3) (white light); 2V = 47(1)°; slight r > v dispersion; orientation Z = b, X ≈ a, Y ≈ c; and pleochroism X very pale purple, Y purple, Z blue green (X << Z < Y). The Raman spectrum is consistent with the presence of tellurate, OH, and H2O. Electron-microprobe analyses gave the empirical formula (Mg1.10Cu0.93Te0.96Sb0.01)Σ3O12H14.12. The mineral is monoclinic, space group P21/c, with a 9.6838(5), b 5.75175(19), c 17.6339(12) Å, β 90.553(6)°, V 982.14(9) Å3, and Z = 4. The five strongest X-ray powder diffraction lines are [dobs Å(I)(hkl)]: 8.77(100)(002), 4.824(71)(200,111), 4.248(85)(-202,202), 2.419(50)(400,024), and 1.8929(48(-226,226)). Pararaisaite is dimorphous with raisaite. The structure contains straight edge-sharing chains of alternating Cu2+O4(OH)2 and Te6+O4(OH)2 octahedra. The chains link to one another via shared octahedral corners to form [Cu2+Te6+O4(OH)2]2– sheets. Interlayer Mg(H2O)6 octahedra link the sheets via hydrogen bonds.
Referenza:
▪ Kampf; A.R., Housley, R.M., Rossman, G.R. (2018): Pararaisaite, the Dimorph of Raisaite, from the North Star Mine, Tintic, Utah, Usa. Canadian Mineralogist, 56, 811-820.
Abstract:
Pararaisaite, Cu2+Mg[Te6+O4(OH)2]·6H2O, is a new mineral from the North Star mine, Tintic district, Juab County, Utah, USA. It is an oxidation-zone mineral occuring in vugs in a matrix of massive quartz with embedded crystals of baryte and goldfieldite. Crystals are deep blue, striated prisms up to 0.4 mm in length, elongated on [010] and exhibiting the forms {100}, {001}, {102}, {10-2}, and {114}. The mineral is transparent with vitreous luster, white streak, Mohs hardness 2½, brittle tenacity, splintery fracture, and two cleavages: perfect on {001} and good on {100}. The measured density is 2.85(2) g/cm3. Pararaisaite is biaxial (+) with α = 1.600(2), β = 1.616(2), γ = 1.713(3) (white light); 2V = 47(1)°; slight r > v dispersion; orientation Z = b, X ≈ a, Y ≈ c; and pleochroism X very pale purple, Y purple, Z blue green (X << Z < Y). The Raman spectrum is consistent with the presence of tellurate, OH, and H2O. Electron-microprobe analyses gave the empirical formula (Mg1.10Cu0.93Te0.96Sb0.01)Σ3O12H14.12. The mineral is monoclinic, space group P21/c, with a 9.6838(5), b 5.75175(19), c 17.6339(12) Å, β 90.553(6)°, V 982.14(9) Å3, and Z = 4. The five strongest X-ray powder diffraction lines are [dobs Å(I)(hkl)]: 8.77(100)(002), 4.824(71)(200,111), 4.248(85)(-202,202), 2.419(50)(400,024), and 1.8929(48(-226,226)). Pararaisaite is dimorphous with raisaite. The structure contains straight edge-sharing chains of alternating Cu2+O4(OH)2 and Te6+O4(OH)2 octahedra. The chains link to one another via shared octahedral corners to form [Cu2+Te6+O4(OH)2]2– sheets. Interlayer Mg(H2O)6 octahedra link the sheets via hydrogen bonds.
Marco E. Ciriotti
«Things are interesting only in so far as they relate themselves to other things»
«Things are interesting only in so far as they relate themselves to other things»
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