I. Lykova, R. Rowe, G. Poirier, Henrik Friis, Kate Helwig
{"title":"Mckelveyite group minerals – Part 3: Bainbridgeite-(YCe), Na2Ba2YCe(CO3)6 ⋅ 3H2O, a new species from Mont Saint-Hilaire, Canada","authors":"I. Lykova, R. Rowe, G. Poirier, Henrik Friis, Kate Helwig","doi":"10.5194/ejm-36-183-2024","DOIUrl":null,"url":null,"abstract":"Abstract. The new mckelveyite group mineral bainbridgeite-(YCe), ideally Na2Ba2YCe(CO3)6 ⋅ 3H2O, was found at Mont Saint-Hilaire, Quebec, Canada. Bainbridgeite-(YCe) occurs as pseudotrigonal and pseudohexagonal hemimorphic crystals that show platy, columnar, tabular, cone-shaped, barrel-shaped, saucer-shaped, or spindle-shaped habit. They often form stacked or parallel growth aggregates, rosettes, and groups of radiating crystals. The crystals are usually less than 1 mm in size. Bainbridgeite-(YCe) varies in colour from pale yellow to yellow, grey to almost black, bluish grey, green-grey, or white. The streak is white; the lustre is vitreous. The mineral has no cleavage. The Mohs hardness is 3. Dcalc is 3.49 g cm−3. Bainbridgeite-(YCe) is optically biaxial (+), α= 1.572(2), β= 1.586(2), γ= 1.628(2), 2 V (calc.) = 62∘, 2 V (meas.) = 45(4)∘(589 nm). The IR spectrum is reported. The composition (wt %, average of five analyses) is Na2O 6.86, CaO 0.59, SrO 4.01, BaO 25.71, Y2O3 8.24, La2O3 4.96, Ce2O3 8.38, Pr2O3 0.48, Nd2O3 1.87, Sm2O3 0.23, Gd2O3 0.67, Tb2O3 0.07, Dy2O3 1.38, Ho2O3 0.32, Er2O3 0.94, Tm2O3 0.08, Yb2O3 0.49, CO2 27.03, H2O 5.67, total 97.98. The empirical formula of the holotype calculated on the basis of six cations is as follows: Na2.11Ca0.10Sr0.37Ba1.60Y0.70La0.29Ce0.49Pr0.03Nd0.11Sm0.01Gd0.03Dy0.07Ho0.02Er0.05 Yb0.02(CO3)5.86(H2O)3.00. The mineral is triclinic, P1, a= 9.1079(2) Å, b= 9.1066(3) Å, c= 6.9332(2) Å, α= 102.861(2)∘, β= 116.148(2)∘, γ= 60.181(2)∘, V= 447.85(2) Å3, and Z= 1. The strongest reflections of the powder X-ray diffraction pattern [d,Å(I)(hkl)] are 6.22(42)(001, 1‾1‾1, 1‾01), 4.430(100)(01‾1, 2‾1‾1, 120), 4.094(37)(1‾2‾1, 1‾11, 210, 111), 3.263(26)(11‾1, 2‾1‾2, 121), 2.888(67)(1‾2‾2, 1‾12, 211), 2.633(38)(3‾01, 030, 3‾3‾1), 2.263(23)(2‾21, 2‾4‾1, 4‾2‾1). 2.010(20)(03‾2, 3‾3‾3, 3‾03, 301, 032, 331). The crystal structure, solved and refined from single-crystal X-ray diffraction data (R1= 0.040), is of the weloganite type.\n","PeriodicalId":11971,"journal":{"name":"European Journal of Mineralogy","volume":null,"pages":null},"PeriodicalIF":1.8000,"publicationDate":"2024-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"European Journal of Mineralogy","FirstCategoryId":"89","ListUrlMain":"https://doi.org/10.5194/ejm-36-183-2024","RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"MINERALOGY","Score":null,"Total":0}
引用次数: 0
Abstract
Abstract. The new mckelveyite group mineral bainbridgeite-(YCe), ideally Na2Ba2YCe(CO3)6 ⋅ 3H2O, was found at Mont Saint-Hilaire, Quebec, Canada. Bainbridgeite-(YCe) occurs as pseudotrigonal and pseudohexagonal hemimorphic crystals that show platy, columnar, tabular, cone-shaped, barrel-shaped, saucer-shaped, or spindle-shaped habit. They often form stacked or parallel growth aggregates, rosettes, and groups of radiating crystals. The crystals are usually less than 1 mm in size. Bainbridgeite-(YCe) varies in colour from pale yellow to yellow, grey to almost black, bluish grey, green-grey, or white. The streak is white; the lustre is vitreous. The mineral has no cleavage. The Mohs hardness is 3. Dcalc is 3.49 g cm−3. Bainbridgeite-(YCe) is optically biaxial (+), α= 1.572(2), β= 1.586(2), γ= 1.628(2), 2 V (calc.) = 62∘, 2 V (meas.) = 45(4)∘(589 nm). The IR spectrum is reported. The composition (wt %, average of five analyses) is Na2O 6.86, CaO 0.59, SrO 4.01, BaO 25.71, Y2O3 8.24, La2O3 4.96, Ce2O3 8.38, Pr2O3 0.48, Nd2O3 1.87, Sm2O3 0.23, Gd2O3 0.67, Tb2O3 0.07, Dy2O3 1.38, Ho2O3 0.32, Er2O3 0.94, Tm2O3 0.08, Yb2O3 0.49, CO2 27.03, H2O 5.67, total 97.98. The empirical formula of the holotype calculated on the basis of six cations is as follows: Na2.11Ca0.10Sr0.37Ba1.60Y0.70La0.29Ce0.49Pr0.03Nd0.11Sm0.01Gd0.03Dy0.07Ho0.02Er0.05 Yb0.02(CO3)5.86(H2O)3.00. The mineral is triclinic, P1, a= 9.1079(2) Å, b= 9.1066(3) Å, c= 6.9332(2) Å, α= 102.861(2)∘, β= 116.148(2)∘, γ= 60.181(2)∘, V= 447.85(2) Å3, and Z= 1. The strongest reflections of the powder X-ray diffraction pattern [d,Å(I)(hkl)] are 6.22(42)(001, 1‾1‾1, 1‾01), 4.430(100)(01‾1, 2‾1‾1, 120), 4.094(37)(1‾2‾1, 1‾11, 210, 111), 3.263(26)(11‾1, 2‾1‾2, 121), 2.888(67)(1‾2‾2, 1‾12, 211), 2.633(38)(3‾01, 030, 3‾3‾1), 2.263(23)(2‾21, 2‾4‾1, 4‾2‾1). 2.010(20)(03‾2, 3‾3‾3, 3‾03, 301, 032, 331). The crystal structure, solved and refined from single-crystal X-ray diffraction data (R1= 0.040), is of the weloganite type.
期刊介绍:
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