Levyne Series Levyne-Ca     |(Ca0.5,Sr,K,Na)6(H2O)17| [Al6Si12O36]
Levyne-Na     |(Na,K,Ca0.5)6(H2O)17| [Al6Si12O36]
       
Morphology:    
  Hexagonal crystals, thin tabular, on {0001}, modified by {1011} or {1021} dipyramids. Probably all natural crystals are penetration, rotation twins on [0001]. The levyne from most occurrences is covered with a thin layer of fine-grained, epitaxially oriented erionite Levyne
 
Physical properties:
 

Cleavage: {1010} good; {0001} parting.
Hardness:  4 - 4.5. 
D = 2.04 - 2.17 gm/cm3.
Luster: vitreous.
Streak: white.
  Levyne-Ca with a thin coating of erionite on smectite         balls. Oberwiddersheim, Vogelsberg, Hessen, Germany.  © Volker Betz.
Optical properties:            
 

Color: Colorless white, may be stained grayish, greenish, yellowish by impurities; colorless in thin section.
Uniaxial (-).  ω 1.489 - 1.510, ε 1.487 - 1.502,  δ 0.001 - 0.008

  
   
Crystallography:  
  Unit cell:    
  levyne-Ca   a  13.338, c 23.014 Å  (Passaglia et al. 1974, Merlino et al. 1975)
  levyne-Na   a  13.380, c 22.684 Å  (Mizota et al. 1974)
       
Names:  
  Levyne was named by Brewster (1825) for Armand Lévy (1794-1841) mathematician and crystallographer, Université de Paris. The first descriptions were based on type locality material from Dalsnypen on Sandoy, Faroe Islands. The name has been raised to series status by Coombs et al. (1997), encompassing two new species names: levyne-Ca for the more common composition with the type example from Dalsnypen, Faroe Islands, and levyne-Na for sodic compositions with the type example from Chojabaru, Nagasaki Prefecture, Japan.
       
Crystal structure:  
 

The framework topology consists of stacking 6-rings in the sequence AABCCABBC… (Barrer and Kerr 1959, Merlino et al. 1975). The repeat distance of this long sequence is about 22.90 Å. Between like pairs of 6-membered rings are two levyne cages (LEV), which contain the non-framework cations and H2O molecules. Analyses of T-O bonds lengths by Merlino et al. (1975), show that there is no Si, Al order in the 6-membered rings. However, Sacerdoti (1996) did find evidence of some order.
Non-framework cations occupy five different cation sites (red in the figure), all in a column within the levyne cages.


Levyne


C1 is near the double 6-membered ring, where it bonded to three of the oxygens and to three H2O molecules, and is fully occupied by Ca ions. C2 is nearly in the centre of the cage surrounded by H2O molecules. C3 and C4 are two nearby sites that cannot be simultaneously occupied, and C5, located in the centre of the single 6-ring. In those crystals, for which structures have been refined, occupancy of C2 through C5 sites is less than 30%.
   
Chemical composition:
  Minerals with the levyne structure exhibit a limited range of compositional variation, both in the Si/Al content of the framework and in non-framework cations. The framework composition varies from TSi = 0.62 to 0.69, still a small variation around the average unit cell content of [Al6Si12O36]. Other cations, such as Sr and Mg, occur in minor amounts with rare exceptions.
   
Occurrences:  
 

Levyne is an uncommon zeolite, but all occurrences are in cavities of basalt. Associated minerals include erionite, chabazite, phillipsite, natrolite, analcime, thomsonite, and many others. Some of the well known localities for levyne are Sandoy Island, Faroe Islands; many localities in eastern Iceland; Dozen, Oki Islands, Japan; Victoria, Australia; Goble, Beech Creek and other localities in Oregon and in Washington; Table Mountain, Colorado, United States. These and other occurrences are described by Tschernich (1992).
Walker (1960) reports the occurrence of levyne in the analcime zone in the lavas of eastern Iceland. This zone immediately underlies the chabazite-thomsonite zone, suggesting that levyne forms at slightly higher temperatures.
       
References:  
 

Barrer, R.M. and Kerr, I.S. 1959. Intracrystalline channels in levynite and some related zeolites. Trans. Faraday Soc. 55, 1915-1923.

Brewster, D. 1825. Description of levyne, a new mineral species. Edinb. J. Sci., 2, 332-334.

Coombs, D.S., Alberti, A., Armbruster, T., Artioli, G., Colella, C., Galli, E., Grice, J.D., Liebau, F., Mandarino, J.A., Minato, H., Nickel, E.H., Passaglia, E., Peacor, D.R., Quartieri, S., Rinaldi, R., Ross, M., Sheppard, R.A., Tillmanns, E., and Vezzalini, G. 1997. Recommended nomenclature for zeolite minerals: Report of the Subcommittee on Zeolites of the International Mineralogical Association, Commission on New Minerals and Mineral Names. Can. Min., 35, 1571-1606.

Galli, E., Rinaldi, R. and Modena, C. 1981. Crystal chemistry of levynes. Zeolites 1, 157-160.

Merlino, S., Galli, E. and Alberti, A. 1975. The crystal structure of levyne. Tschermaks. Mineral. Petrogr. Mitt. 22, 117-129.

Mizota, T., Shibuya, G., Shmazu, M. and Takeshita, Y. 1974. Mineralogical studies on levyne and erionite from Japan. Mem. Geol. Soc. Japan, 11, 283-290.

Passaglia, E., Galli, E., Rinaldi, R. 1974. Levynes and erionites from Sardinia, Italy. Contrib. Mineral. Petrol. 43, 253-259.

Sacerdoti, M. 1996. New refinements of the crystal structure of levyne using twinned crystals. N.  Jahrb. Mineral. Mh. 1956, 114-124.

Tschernich, R.W. 1992 Zeolites of the World, Geoscience Press, Phoenix, Arizona. 563 pp.

Walker, G.P.L. 1960. Zeolite zones and dike distribution in relation to the structure of the basalts of eastern Iceland. Jour. Geol. 68, 515-528.