| Title | Probertita, NaCaB5O95H2O, de Tincalayu, Salta, Argentina
[Probertite, NaCaB5O95H2O, from Tincalayu, Salta, Argentina] |
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| Full Reference | Aristarain, Lorenzo Francisco (1969) Probertita, NaCaB5O95H2O, de Tincalayu, Salta, Argentina [Probertite, NaCaB5O95H2O, from Tincalayu, Salta, Argentina]. Revista del Museo de la Plata, 10 (95) 277-292 |
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| Plain Text | Aristarain, Lorenzo Francisco (1969) Probertita, NaCaB5O95H2O, de Tincalayu, Salta, Argentina [Probertite, NaCaB5O95H2O, from Tincalayu, Salta, Argentina]. Revista del Museo de la Plata, 10 (95) 277-292 |
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| Abstract/Notes | The physical and chemical characteristics of the mineral probertite (NaCaBs °95 H2 0) found in the Tincalayu mine, Salta, Argentina, included in dense ulexite, form nodules up to 2 cm in diameter made up of elongated crystals according to [001] that measure up to 5 mm long and 1 mm section in radial arrangement. There are also well-formed, idiomorphous individual crystals contained in borax and kernite, measuring 0.5 mm in length by 0.1 mm in width, elongated along the c axis. It is transparent and colorless and has a vitreous shine, which in the case of isolated crystals is very intense; It does not present fluorescence or phosphorescence. It crystallizes in the monoclinic system, prismatic class 21m; The predominant form is {110}, with {O1O} and {100} being observable with much less development, and at the extremes are {OO1}, {101 },{111} AND {111} (indices with the new cell P 2 ¡la). It has 3 cleavages parallel to {11O} perfect, {010 }good and {1OO}poor; The hardness is 31/2, the measured density is 2.133 and the calculated density is 2.130 g cm3. The optical properties are: biaxic (+), c< = 1.516, B = 1.525, i) = 1.546, ± 0.001 light Na), birefringence 0.030.2 V = 66° (measured) and 68° (calculated), Y = b, Z "c = 17°, r>vy elongation (+). The space group is P 2 ¡I a, a = 13.421 (1), b =12.558 (1), c = 6.591 (1) A, B = 100° 01' (5), volume 1093.9 A3, a: b: c=1.0687: 1:0.5248.Z=4.The most intense lines in dust diagrams are at A9.09 (100 ), 2,925 (30), 6,61 (28), 3,993 (25), 4,553 (21), 3,537 (18), 3,304 (17), 1,803 (17), 2,885 (l6) and 2,835 (13). A chemical analysis gives by weight %: CaO 13.56; MgO 0.09; Nap 9.47, BP3 46.45, HzÜ 26.96 and insoluble 3.47 (by difference), totallOO,OO. The infrared spectrum is presented; The mineral is slightly soluble in hot or cold water but easily dissolves in dilute acids. |
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