Reference:
▪ Haring, M. & McDonald, A.M. (2017): Nolzeite, Na(Mn,□)2[Si3(B,Si)O9(OH)2]•2H2O, a new pyroxenoid mineral. Mineralogical Magazine, 81, 183–197.
Abstract:
Nolzeite, Na(Mn,□)2[Si3(B,Si)O9(OH)2]•2H2O, is a new mineral found in altered sodalite syenite at the Poudrette quarry, La Vallée-du-Richelieu, Montérégie (formerly Rouville County), Québec, Canada. Crystals are colourless to pale green and are acicular with average dimensions of 5 x 8 x 55 μm. They occur as radiating to loose, randomly oriented groupings within vugs associated with aegirine, nepheline, sodalite, eudialyte-group minerals, analcime, natron, pyrrhotite, catapleiite, steedeite and the unidentified mineral, UK80. Nolzeite is non-pleochroic, biaxial, with nmin = 1.616(2) and nmax = 1.636(2) and has a positive elongation. The average of six chemical analyses gave the empirical formula: Na1.04(Mn1.69□0.24Fe0.05Ca0.02)Σ=2.00(Si2.96S0.04)Σ=3.00(B0.70Si0.30)Σ=1.00O9(OH)2•2HO based on 13 anions. The Raman spectrum shows six distinct bands occurring at ~ 3600 – 3300 cm -1 and 1600 – 1500 cm-1 (O-H and H-O-H bending),1300 – 1200 cm-1 (B-OH bending), 1030 – 800 cm-1 (Si-O-Si stretching) as well as 700 – 500 cm-1 and 400 – 50 cm-1 (Mn-O and Na-O bonding, respectively). The FTIR spectrum for nolzeite shows bands at ~ 2800 – 3600 cm-1 (O-H) stretching, a moderately sharp band at 1631 cm-1 (H-O-H) bending, strong, sharp bands at ~650 – 700 cm-1, ~ 800 – 840 cm-1, and ~ 900 – 1100 cm-1 (Si-O and B-O) bonds. Nolzeite is triclinic, crystallizing in space group P-1 with a 6.894(1), b 7.632(2), c 11.017(2) Å, α 108.39(3), β 99.03, γ 103.05(3)°, V 519.27 Å3, and Z = 2. The crystal structure was refined to R =12.37 % and wR2 = 31.07 % for 1361 reflections (Fo > 4σFo). It is based on chains of tetrahedra with a periodicity of three (i.e., a dreier chain) consisting of three symmetrically independent SiO4 tetrahedra forming C-shaped clusters closed by BO2(OH)2 tetrahedra, producing single loop-branched dreier borosilicate chains. The chains are linked through shared corners to double chains of edge-sharing MnO5(OH) octahedra. Nolzeite is a chain silicate closely related to steedeite and members of the sérandite-pectolite series. Paragenetically, nolzeite is late-stage, likely forming under alkaline conditions and over a narrow range of low pressures and temperatures.
▪ Haring, M. & McDonald, A.M. (2017): Nolzeite, Na(Mn,□)2[Si3(B,Si)O9(OH)2]•2H2O, a new pyroxenoid mineral. Mineralogical Magazine, 81, 183–197.
Abstract:
Nolzeite, Na(Mn,□)2[Si3(B,Si)O9(OH)2]•2H2O, is a new mineral found in altered sodalite syenite at the Poudrette quarry, La Vallée-du-Richelieu, Montérégie (formerly Rouville County), Québec, Canada. Crystals are colourless to pale green and are acicular with average dimensions of 5 x 8 x 55 μm. They occur as radiating to loose, randomly oriented groupings within vugs associated with aegirine, nepheline, sodalite, eudialyte-group minerals, analcime, natron, pyrrhotite, catapleiite, steedeite and the unidentified mineral, UK80. Nolzeite is non-pleochroic, biaxial, with nmin = 1.616(2) and nmax = 1.636(2) and has a positive elongation. The average of six chemical analyses gave the empirical formula: Na1.04(Mn1.69□0.24Fe0.05Ca0.02)Σ=2.00(Si2.96S0.04)Σ=3.00(B0.70Si0.30)Σ=1.00O9(OH)2•2HO based on 13 anions. The Raman spectrum shows six distinct bands occurring at ~ 3600 – 3300 cm -1 and 1600 – 1500 cm-1 (O-H and H-O-H bending),1300 – 1200 cm-1 (B-OH bending), 1030 – 800 cm-1 (Si-O-Si stretching) as well as 700 – 500 cm-1 and 400 – 50 cm-1 (Mn-O and Na-O bonding, respectively). The FTIR spectrum for nolzeite shows bands at ~ 2800 – 3600 cm-1 (O-H) stretching, a moderately sharp band at 1631 cm-1 (H-O-H) bending, strong, sharp bands at ~650 – 700 cm-1, ~ 800 – 840 cm-1, and ~ 900 – 1100 cm-1 (Si-O and B-O) bonds. Nolzeite is triclinic, crystallizing in space group P-1 with a 6.894(1), b 7.632(2), c 11.017(2) Å, α 108.39(3), β 99.03, γ 103.05(3)°, V 519.27 Å3, and Z = 2. The crystal structure was refined to R =12.37 % and wR2 = 31.07 % for 1361 reflections (Fo > 4σFo). It is based on chains of tetrahedra with a periodicity of three (i.e., a dreier chain) consisting of three symmetrically independent SiO4 tetrahedra forming C-shaped clusters closed by BO2(OH)2 tetrahedra, producing single loop-branched dreier borosilicate chains. The chains are linked through shared corners to double chains of edge-sharing MnO5(OH) octahedra. Nolzeite is a chain silicate closely related to steedeite and members of the sérandite-pectolite series. Paragenetically, nolzeite is late-stage, likely forming under alkaline conditions and over a narrow range of low pressures and temperatures.