Alloriite, Na5K1.5Ca(Si6Al6O24)(SO4)(OH)0.5 · H2O, a new mineral species of the cancrinite group (original) (raw)

Abstract

Alloriite, a new mineral species, has been found in volcanic ejecta at Mt. Cavalluccio (Campagnano municipality, Roma province, Latium region, Italy) together with sanidine, biotite, andradite, and apatite. The mineral is named in honor of Roberto Allori (b. 1933), an amateur mineralogist and prominent mineral collector who carried out extensive and detailed field mineralogical investigations of volcanoes in the Latium region. Alloriite occurs as short prismatic and tabular crystals up to 1.5 × 2 mm in size. The mineral is colorless, transparent, with a white streak and vitreous luster. Alloriite is not fluorescent and brittle; the Mohs’ hardness is 5. The cleavage is imperfect parallel to {10\(\overline 1 \)0}. The density measured with equilibration in heavy liquids is 2.35g/cm3 and calculated density (D calc) is 2.358 g/cm3 (on the basis of X-ray single-crystal data) and 2.333 g/cm3 (from X-ray powder data). Alloriite is optically uniaxial, positive, ω = 1.497(2), and ɛ = 1.499(2). The infrared spectrum is given. The chemical composition (electron microprobe, H2O determined using the Penfield method, CO2, with selective sorption, wt %) is: 13.55 Na2O, 6.67 K2O, 6.23 CaO, 26.45 Al2O3, 34.64 SiO2, 8.92 SO3, 0.37 Cl, 2.1 H2O, 0.7 CO2, 0.08-O = Cl2, where the total is 99.55. The empirical formula (Z = 1) is Na19.16K6.21Ca4.87(Si25.26Al22.74O96)(SO4)4.88(CO3)0.70Cl0.46(OH)0.76 · 4.73H2O. The simplified formula (taking into account the structural data, Z = 4) is: [Na(H2O)][Na4K1.5(SO4)] · [Ca(OH,Cl)0.5](Si6Al6O24). The crystal structure has been studied (R = 0.052). Alloriite is trigonal, the space group is P_31_c; the unit-cell dimensions are a = 12.892(3), c = 21.340(5) Å, and V = 3071.6(15) Å3. The crystal structure of alloriite is based on the same tetrahedral framework as that of afghanite. In contrast to afghanite containing clusters [Ca-Cl]+ and chains ...Ca-Cl-Ca-Cl..., the new mineral contains clusters [Na-H2O]+ and chains ...Na-H2O-Na-H2O.... The strongest reflections in the X-ray powder diffraction pattern [d, Å (I, %)(hkl)] are: 11.3(70)(100), 4.85(90)(104), 3.76(80)(300), 3.68(70)(301), 3.33(100)(214), and 2.694(70)(314, 008). The type material of alloriite is deposited in the Fersman Mineralogical Museum, Russian Academy of Sciences, Moscow. The registration number is 3459/1.

Access this article

Log in via an institution

Subscribe and save

Buy Now

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Similar content being viewed by others

References

  1. P. Ballirano, A. Maras, and P. R. Buseck, “Crystal Chemistry and IR Spectroscopy of Cl-and SO4-Bearing Cancrinite-Like Minerals,” Am. Mineral. 81, 1003–1012 (1996).
    Google Scholar
  2. P. Ballirano, A. Maras, P. R. Buseck, et al., “Improved Powder X-Ray Data for Cancrinites: I. Afghanite,” Powder Diffraction 9(1), 68–73 (1994).
    Google Scholar
  3. P. Ballirano, E. Bonaccorsi, A. Maras, and S. Merlino, “Crystal Structure of Afghanite, the Eightlayer Member of the Cancrinite Group: Evidence for Long-Range Si, Al Ordering,” Eur. J. Mineral. 9, 21–30 (1997).
    Google Scholar
  4. P. Bariand, F. Cesbron, and R. Giraud, “Une Nouvelle Espéce Minerale: l’Afghanite de Sar-e-Sang, Badakhshan, Afghanistan. Comparison Avec les Minéraux du Groupe de la Cancrinite,” Bull. Soc. Franc. Miner. Gristallogr 91, 34–42 (1968).
    Google Scholar
  5. E. Bonaccorsi and S. Merlino, “Modular Microporous Minerals: Cancrinite-Davyne Group and C-S-H Phases,” Reviews in Mineral. and Geochem. 57, 241–290 (2005).
    Article Google Scholar
  6. G. Della Ventura, F. Bellatreccia, and E. Bonaccorsi, “CO2 in Minerals of the Cancrinite-Sodalite Group: Piglianoite,” Eur. J. Mineral. 17, 847–851 (2005).
    Article Google Scholar
  7. E. A. Pobedimskaya, R. K. Rastsvetaeva, L. E. Terent’eva, and A. N. Sapozhnikov, “Crystal Structure of Afghanite,” Dokl. Akad. Nauk SSSR 320(4), 882–886 (1991).
    Google Scholar
  8. R. K. Rastsvetaeva, E. A. Pobedimskaya, L. E. Terent’eva, and A. N. Sapozhnikov, “Structural Features of Afghanite and Its Place Among Minerals of Cancrinite Group,” Kristallografiya 38(2), 94–103 (1993).
    Google Scholar

Download references

Author information

Authors and Affiliations

  1. Institute of Problems of Chemical Physics, Russian Academy of Sciences, Chernogolovka, Moscow oblast, 142432, Russia
    N. V. Chukanov
  2. Institute of Crystallography, Russian Academy of Sciences, Leninskii pr. 59, Moscow, 117333, Russia
    R. K. Rastsvetaeva
  3. Faculty of Geology, Moscow State University, Vorob’evy gory, 119899, Russia
    I. V. Pekov
  4. NPO Regenerator, 3d proezd Mar’inoi Roshchi, 40, Moscow, 127018, Russia
    A. E. Zadov

Authors

  1. N. V. Chukanov
    You can also search for this author inPubMed Google Scholar
  2. R. K. Rastsvetaeva
    You can also search for this author inPubMed Google Scholar
  3. I. V. Pekov
    You can also search for this author inPubMed Google Scholar
  4. A. E. Zadov
    You can also search for this author inPubMed Google Scholar

Corresponding author

Correspondence toN. V. Chukanov.

Additional information

Original Russian Text © N.V. Chukanov, R.K. Rastsvetaeva, I.V. Pekov, A.E. Zadov, 2007, published in Zapiski Rossiiskogo Mineralogicheskogo Obshchestva, 2007, No. 1, pp. 82–89.

A new mineral alloriite and its name were accepted by the Commission on New Minerals and Mineral Names, Russian Mineralogical Society, May 8, 2006. Approved by the Commission on New Minerals and Mineral Names, International Mineralogical Association, August 2, 2006.

Rights and permissions

About this article

Cite this article

Chukanov, N.V., Rastsvetaeva, R.K., Pekov, I.V. et al. Alloriite, Na5K1.5Ca(Si6Al6O24)(SO4)(OH)0.5 · H2O, a new mineral species of the cancrinite group.Geol. Ore Deposits 49, 752–757 (2007). https://doi.org/10.1134/S1075701507080090

Download citation

Keywords