Calcinaksite, KNaCa(Si4O10) H2O, a new mineral from the Eifel volcanic area, Germany
| dc.creator | Chukanov, N.V. | |
| dc.creator | Aksenov, S.M. | |
| dc.creator | Rastsvetaeva, R.K. | |
| dc.creator | Blass, G. | |
| dc.creator | Varlamov, D.A. | |
| dc.creator | Pekov, I.V. | |
| dc.creator | Belakovskiy, D.I. | |
| dc.creator | Gurzhiy, Vladislav V. | |
| dc.date | 2016-05-06T14:03:17Z | |
| dc.date | 2016-05-06T14:03:17Z | |
| dc.date | 2015-08 | |
| dc.date.accessioned | 2019-03-31T11:39:20Z | |
| dc.date.available | 2019-03-31T11:39:20Z | |
| dc.description | The new mineral calcinaksite, ideally KNaCa(Si4O10) · H2O, the first hydrous and Ca-dominant member of the litidionite group, is found in a xenolith of metamorphosed carbonate-rich rock from the southern lava flow of the Bellerberg volcano, Eastern Eifel region, Rheinland-Pfalz, Germany. It is associated with wollastonite, gehlenite, brownmillerite, Ca2SiO4 (larnite or calcio-olivine), quartz, aragonite, calcite, jennite, tobermorite and ettringite. Calcinaksite occurs as clusters of colourless to light-grey subhedral prismatic crystals. The mineral is brittle, with Mohs’ hardness of 5; Dmeas is 2.62(2) g/cm3 and Dcalc is 2.623 g/cm3. The IR spectrum shows the presence of H2O molecules forming three different H-bonds. Calcinaksite is optically biaxial (+), α = 1.542(2), β = 1.550(2), γ = 1.565(3), 2V meas = 75(10). The chemical composition (electron-microprobe data, H2O determined by the Alimarin method, wt%) is: Na2O 6.69, K2O 12.01, CaO 15.04, FeO 0.59, SiO2 61.46, H2O 4.9, total 100.69. The empirical formula is H2.11 K0.99Na0.84Ca1.04Fe0.03Si3.98O11. The crystal structure was solved and refined to R 1 = 0.053, wR 2 = 0.075 based upon 3057 reflections having I > 3σ(I). Calcinaksite is triclinic, space group P 1¯¯¯ , a = 7.021(2), b = 8.250(3), c = 10.145(2) Å. α = 102.23(2)°, β = 100.34(2)°, γ = 115.09(3)°, V = 495.4(3) Å3, Z = 2. The strongest reflections of the X-ray powder pattern [d, Å (I,%) (hkl)] are: 3.431 (70) (−121, −211, −210, 012, 0–22), 3.300 (67) (−031), 3.173 (95) (−103, −201, −220, 003, 111), 3.060 (100) (−212, 2–11, −221, 200, −1-13, 021, −202), 2.851 (83) (0–23, −122, 1–13, 1–31), 2.664 (62) (1–23, −222, 201). | |
| dc.identifier | 0930-0708 | |
| dc.identifier | 10.1007/s00710-015-0376-4 | |
| dc.identifier | http://hdl.handle.net/11701/2252 | |
| dc.identifier.uri | https://repository.geologyscience.ru/handle/123456789/1877 | |
| dc.language | en | |
| dc.publisher | Springer | |
| dc.relation | Mineralogy and Petrology;V. 109. Issue 4 | |
| dc.title | Calcinaksite, KNaCa(Si4O10) H2O, a new mineral from the Eifel volcanic area, Germany | |
| dc.type | Article |