The new mineral species richardsollyite, TlPbAsS3, was discovered in the Lengenbach quarry, Imfeld, Binn Valley, Canton Valais, Switzerland, intimately associated with hutchinsonite and baryte. It occurs as grey-black crystals, up to 750 μm, with a metallic lustre. Under the reflected-light microscope, richardsollyite is grey, with bright-red internal reflections; anisotropy is distinct, with greyish-white to bluish rotation tints. Reflectance values for the four COM wavelengths are [Rmin, Rmax(%), (λ)]: 27.9, 29.8 (471.1 nm); 27.8, 31.0 (548.3 nm); 27.3, 30.8 (586.6 nm); and 27.0, 30.5 (652.3 nm). Electron microprobe analysis gave (in wt%): Tl 34.72(51), Pb 35.45(20), As 12.80(14), Sb 0.04(1), S 16.22(13), total 99.24(47). On the basis of 6 atoms per formula unit, the chemical formula is Tl1.001Pb1.008(As1.007Sb0.002)Σ1.009S2.982. The main diffraction lines [d in à (intensity) hkl] are: 4.23 (80) 1 0 2; 3.875 (70) 2 1 1; 3.762 (100) 2 1 0, 1 2 0; 3.278 (70) 1 0 2; 2.931 (70) 0 2 2; 2.714 (70) 1 1 3; and 2.622 (80) 3 1 2. Richardsollyite is monoclinic, space group P21/c, with a = 8.8925(2), b = 8.4154(2), c = 8.5754(2) à , β = 108.665(3)°, V = 607.98(3) à 3, Z = 4. The crystal structure was solved and refined to R1= 0.0242 on the basis of 1590 reflections with Fo> 4Ï(Fo). It can be described as formed by (1 0 0) [Pb (AsS3)]-layers sandwiching Tl+cations, and is isostructural with synthetic ABCX3(A = K, Rb, Cs; B = Eu, Ba; C = As, Sb; X = S, Se) compounds. The new mineral is named after Richard Harrison Solly (1851-1925) for his outstanding contribution to the knowledge of the Lengenbach mineralogy during the first flourishing period of Lengenbach investigations, at the beginning of the 20th Century.
Richardsollyite, TlPbAsS3, a new sulfosalt from the Lengenbach quarry, Binn Valley, Switzerland
BIAGIONI, CRISTIAN;
2017-01-01
Abstract
The new mineral species richardsollyite, TlPbAsS3, was discovered in the Lengenbach quarry, Imfeld, Binn Valley, Canton Valais, Switzerland, intimately associated with hutchinsonite and baryte. It occurs as grey-black crystals, up to 750 μm, with a metallic lustre. Under the reflected-light microscope, richardsollyite is grey, with bright-red internal reflections; anisotropy is distinct, with greyish-white to bluish rotation tints. Reflectance values for the four COM wavelengths are [Rmin, Rmax(%), (λ)]: 27.9, 29.8 (471.1 nm); 27.8, 31.0 (548.3 nm); 27.3, 30.8 (586.6 nm); and 27.0, 30.5 (652.3 nm). Electron microprobe analysis gave (in wt%): Tl 34.72(51), Pb 35.45(20), As 12.80(14), Sb 0.04(1), S 16.22(13), total 99.24(47). On the basis of 6 atoms per formula unit, the chemical formula is Tl1.001Pb1.008(As1.007Sb0.002)Σ1.009S2.982. The main diffraction lines [d in à (intensity) hkl] are: 4.23 (80) 1 0 2; 3.875 (70) 2 1 1; 3.762 (100) 2 1 0, 1 2 0; 3.278 (70) 1 0 2; 2.931 (70) 0 2 2; 2.714 (70) 1 1 3; and 2.622 (80) 3 1 2. Richardsollyite is monoclinic, space group P21/c, with a = 8.8925(2), b = 8.4154(2), c = 8.5754(2) à , β = 108.665(3)°, V = 607.98(3) à 3, Z = 4. The crystal structure was solved and refined to R1= 0.0242 on the basis of 1590 reflections with Fo> 4Ï(Fo). It can be described as formed by (1 0 0) [Pb (AsS3)]-layers sandwiching Tl+cations, and is isostructural with synthetic ABCX3(A = K, Rb, Cs; B = Eu, Ba; C = As, Sb; X = S, Se) compounds. The new mineral is named after Richard Harrison Solly (1851-1925) for his outstanding contribution to the knowledge of the Lengenbach mineralogy during the first flourishing period of Lengenbach investigations, at the beginning of the 20th Century.File | Dimensione | Formato | |
---|---|---|---|
Texte_Richardsollyite_Meisser et al_2016_11_14.docx
accesso aperto
Tipologia:
Documento in Pre-print
Licenza:
Creative commons
Dimensione
87.81 kB
Formato
Microsoft Word XML
|
87.81 kB | Microsoft Word XML | Visualizza/Apri |
I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.