This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1896 Excerpt: ... alter into albite or orthoclase; laumontite and stilbite into analcite; chabazite into natrolite; and gismondite into phillipsite. So also alterations into prehnite are recorded on the part of laumontite, scolecite, mesolite, natrolite, and analcite; and the identity of chemical type seems to be almost unquestionable. ...
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This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1896 Excerpt: ... alter into albite or orthoclase; laumontite and stilbite into analcite; chabazite into natrolite; and gismondite into phillipsite. So also alterations into prehnite are recorded on the part of laumontite, scolecite, mesolite, natrolite, and analcite; and the identity of chemical type seems to be almost unquestionable. From the formula here developed all of these alterations become intelligible, and the theory of substitution from normal salts is very emphatically sustained. For the group of zeolites it only remains to summarize the expressions which have been adopted. For starting points the following minerals are taken: Nephelite Al3(Si04)3: N"a3 Albite and orthoclase AlSLj0gR'a Anorthite Al6(Si04)6Ca3 Trisilicic anorthite Al6(Si308)6Ca3 The last compound is purely hypothetical. To these may be added leucite, from which analcite and faujasite are derivable, and the bariumstrontium feldspars which give rise to brewsterite, edingtonite, and harmotome. Brewsterite, as the equivalent of heulandite, and harmotome, as a barium phillipsite, need not be considered further; and as for edingtonite, its constitution is very uncertain. The remaining zeolites are as follows, with the difference between water of constitution and water of crystallization disregarded, except in the few cases in which the distinction affects the integrity of the molecular type. The symbol X is used to express Si04 or Si308 indiscriminately: Some of these formulae are conditioned by the replacements and alternatives cited in the previous pages and in my former paper upon the zeolites, and they are further modified by the character of the hydration. The expressions for analcite and faujasite, as based upon the leucite type, need not be repeated. The morphological characteristics of the ...
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