MINERALS/Zeolites 593 Table Continued Name Generalized formula Levyne series Levyne Ca Levyne Na Lovdarite Maricopaite Mazzite Merlinoite Mesolite Montesommaite Mordenite Mutinaite Nabesite Natrolite Offretite Pahasapaite Parthe´ite Paulingite series Paulingite K Paulingite Ca Perlialite Phillipsite series Phillipsite Na Phillipsite K Phillipsite Ca Pollucite Roggianite Scolecite Stellerite Stilbite series Stilbite Ca Stilbite Na Terranovaite Thomsonite series Thomsonite Ca Thomsonite Sr Tschernichite Tschortnerite Wairakite Weinebeneite Willhendersonite Yugawaralite (Ca0 5,Na,K)6[Al6Si12O36].17H2O (Ca0 5,Sr,K,Na)6[Al6Si12O36].17H2O (Na,K,Ca0 5)6[Al6Si12O36].17H2O K4Na12[Be8Si28O72].18H2O (Pb7Ca2)[Al12Si36(O,OH)100].nH2O (Mg2 5K2Ca1 5)[Al10Si26O72].30H2O (K,Ca0 5,Ba0 5,Na)10[Al10Si22O64].22H2O Na2Ca2[Al6Si9O30].8H2O K9[Al9Si23O64].10H2O (Na2,Ca,K2)[Al8Si40O96].28H2O Na3Ca4[Al11Si85O192].60H2O Na2BeSi4O10.4H2O Na2[Al2Si3O10].2H2O CaKMg[Al5Si13O36].16H2O (Ca5 5Li3 6K1 2Na0 2u13 5)Li8[Be24P24O96].38H2O Ca2[Al4Si4O15(OH)2].4H2O (K,Ca0 5,Na,Ba0 5)10[Al10Si32O84].27 44H2O (K,Ca0 5,Na)10[Al10Si32O84].44H2O (Ca0 5,K,Na,Ba0 5)10[Al10Si32O84].27 34H2O K9Na(Ca,Sr)[Al12Si24O72].15H2O (K,Na,Ca0 5)x [Alx Si16-xO32].12H2O, x 3.8 6.4 (Na,K,Ca0 5)x [Alx Si16-xO32].12H2O, x 3.7 6.7 (K,Na,Ca0 5)x [Alx Si16-xO32].12H2O, x 3.8 6.4 (Ca0 5,K,Na)x [Alx Si16-xO32],12H2O, x 4.1 6.8 (Cs,Na)[AlSi2O6].nH2O (Cs ỵ n 1) Ca2[BeAl2Si4O13(OH)2].2 2.5H2O Ca[Al2Si3O10].3H2O Ca4[Al8Si28O72].28H2O (Ca0 5,Na,K)9[Al9Si27O72].30H2O (Ca0 5,Na,K)9[Al9Si27O72].30H2O (Na,K,Ca0 5)9[Al9Si27O48].28H2O NaCa[Al3Si17O40].13H2O (Ca,Sr)2Na[Al5Si5O20].6 7H2O Ca2Na[Al5Si5O20].6H2O (Sr,Ca)2Na[Al5Si5O20].7H2O (Ca,Mg,Na0 5)[Al2Si6O16].8H2O Ca4(K2,Ca,Sr,Ba)3Cu3(OH)8[Al12Si12O48].nH2O Ca[Al2Si4O12].2H2O Ca[Be3PO8(OH)2].4H2O Ca3-xKx[Al6Si6O24].10H2O, x 0.0 2.0 Ca[Al2Si6O16].4H2O Z (Z ¼ number of formula units per unit cell.) Structure type code LEV 1 1 1 1 16 LOV ?MOR MAZ MER NAT MON MOR MFI NAB NAT OFF RHO PAR PAU 1 LTL PHI 16 8 ANA ROG NAT STI STI TER THO 16 BEA TSC ANA WEI CHA YUG Reproduced with permission from Deer WA, Howie RA, Wise WS, and Zussman J (2004) Rock Forming Minerals, Volume 4B Framework Silicates: Silica Minerals, Feldspathoids and the Zeolites London: The Geological Society five tetrahedral sites, sodium cations are bonded within the channels (Figure 3) The bonding of these sodium cations to opposite sides of the channel partially collapses the channel from a possible square cross-section to an elliptical one Each sodium cation is bonded by two water molecules, which are in turn each bonded to two sodium cations The crystal form of chabazite is a rhombohedron that is almost cubic The framework consists of sixmember rings of tetrahedra, which are arranged in the sequence AABBCC (Figure 4) Each different letter represents a different position of the six-member ring around the stacking direction parallel to the c-axis The distribution of aluminium in the tetrahedral sites is nearly random Non-framework cations partially fill four different sites: (i) outside the double six-member ring and bonded with three oxygen atoms of the ring; (ii) near the eight-member ring port of the chabazite cage and bonded with three framework oxygen atoms; (iii) near the centre of the cage and not bonded with the framework; and (iv) at the centre of the eight-member ring Positions (i) and (iii) generally contain most of the cations Crystals of heulandite and clinoptilolite are tabular with a perfect cleavage The framework consists of sheets of tetrahedra with no openings large enough