Heulandites

Hetran teams Hetrazan Heubach method Heulandite Heuristic approach Heuristics Hevea brasiliensis Heveacrumb process Hevea rubber Hexa [100-97-0]... 

Figure 1.74. Zonal sequence of the propylitic alteration in E-W section of the Seigoshi-Toi mine area (Yug = yugawaralite Heu = heulandite Stil = stilbite Opx = orthopyroxene Mont = montmorillonite Mor = mordenite Lm = laumontite Wr = wairakite Chi = chlorite pr = prehnite ep = epidote Py = pyrite Kf = K-feldspar Cpx = clinopyroxene) (Shikazono, 1985a).

Maruyama, S., Liou, J.G. and Cho, M. (1983) Experimental investigation of heulandite-laumontite equilibrium. Ext. Abstr., 4th Int. Symp. on Water-Rock Interaction, Misasa, pp. 305-308. 

Hydrothermal alteration minerals from midoceanic basalt are analcite, stilbite, heulandite, natrolite-mesolite-scolecite series, chlorite and smectite for zeolite facies, prehnite, chlorite, calcite and epidote for prehnite-pumpellyite facies, albite, actinolite, chlorite, epidote, quartz, sphene, hornblende, tremolite, talc, magnetite, and nontronite for green schist facies, hornblende, plagioclase, actinolite, leucoxene, quartz, chlorite, apatite, biotite, epidote, magnetite and sphene for amphibolite facies (Humphris and Thompson, 1978). 

There are many 10-ring zeolites the channel cross-section can be nearly circular, such as with ZSM-5, where the major and minor diameters are 0.56 and 0.54 nm they can be nearly elliptical, such as Heulandite, where the two diameters are 0.76 and 0.30 nm and they can be approximately rectangular, such as the Laumontite, where the diameters are 0.53 and 0.40 nm. There are even more 12-ring zeolites to choose from. The faujasite X and Y have cross-sections that are nearly circular, with diameters of 0.74 nm. The ratio of Si to A1 is a critical parameter, as the trivalent A1 requires a cation such as Na+, but the tetravalent Si does not. There is also a choice of the cation involved, from the monovalent H+, Na+, and K+, to the divalent Mg +, Ca " ", Sr +, and Ba +. 

Fig. 4. "Long-range order coefficients Sj, for heulandite-clinoptilolite series. Reference s number is shown. Empty squares = heulandites full squares = clinoptilolites.

Feng X. and Savin S.M. (1993) Oxygen isotope studies of zeolites stiblite, analcime, heulandite and clinoptilolite, II kinetics and mechanism of isotopic exchange between zeolites and water vapor. Geochim. Cosmochim. Acta 57, 4219-4238. 

Alkali zeolites (especially the more common species natrolite, anal-cite, phillipsite, erionite, scoleite, heulandite, clinoptilolite and... 

He = heulandite Cl = clinoptilolite Mor = mordenite M = mica. Solid solution or continuous compositions are assumed present between analcite and mordenite-clinoptilolite. 

The latter, according to Coombs, is an analcite-heulandite facies which contains other calcic zeolites in more basic rocks. The disappearance of analcite would occur near the heulandite-laumontite transition for calcic zeolites. Thus, calcic zeolites can continue to be stable at higher grades of diagenesis or epimetamorphism than alkali zeolites. 

BOLES (J.R.) 1971. Synthesis of analcime from natural heulandite and clinoptilolite. Amer. Min., 6, 1724-1734. 

Possessing Intrinsic Porosity Some zeolites (heulandite, clinop-tilolite, stilbite)... 

No significant differences have been established between heulandite and laumontite in sedimentary formations in the zones of deep epigenesis (initial metamorphism), on the one hand, and the same minerals in hydro-thermal deposits, on the other. Apparently, this will require more factual data. Nevertheless, the distribution of these zeolites and the associations of clay minerals permit a distinction between the zeolite facies of regional epigenesis-metamorphism and the zeolite mineralization in geothermal areas (recent hydrothermal systems). 

Laumontite-Heulandite Associations in the Coal-Bearing Series in Eastern Siberia... 

The coal-bearing Cretaceous formations of the Verkhoyan area are 400-500 m thick in platform areas and over 2500 m thick in the foredip. In the foredip they extend from the north to southeast for more than 1500 km. Laumontite occurs only in the foredip in sandy packets, 20-100 m thick. Laumontite is absent in platform sections however, in some of them, Ca-zeolites, such as heulandite, desmine, and probably epistilbite, have been found. Although laumontite is widespread throughout the entire Cretaceous formations of the foredip, zeolites in platform sections are rare and have been found mostly in northern regions (19,20). 

Buryanova, E. Z., Bogdanov, V. V., Regularities of the Distribution of Authe-genic Zeolites—Laumontite and Heulandite—in the Sedimentary Rocks of Tarbagatai Coal Field/ Litol. Polezn. I shop. (1967) (2). 

Hetran teams Hetrazan Heubach method Heulandite Heuristic approach Heuristics... 

Ocean), which makes it a good candidate, although another zeolite (clinoptilolite or heulandite) is more important in the Atlantic Ocean. Glauconite, a lAf mica rich in Fe, has also been found growing abundantly in the ocean under slightly oxidizing conditions (10), but since our intermediate model contains no Fe, we shall omit glauconite until Fe is added to the model. For similar reasons, calcite is left out the intermediate model contains no C. 

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