. Annals of the New York Academy of Sciences. Science; Science -- New York (State). 170 ANNALS NEW YORK ACADEMY OF SCIENCES stilbite cannot coexist in equilibrium except at one fixed temperature, which represents a transition point. Although heulandite might very well persist in an unaltered form beyond this point, it should never be deposited from solution simultaneously with stilbite. The replacement of chabazite, heulandite and stilbite by natrolite seems to have been effected with great ease, natrolite needles shooting out across areas of the three'lime zeolites as if no obstacle were offe
. Annals of the New York Academy of Sciences. Science; Science -- New York (State). 170 ANNALS NEW YORK ACADEMY OF SCIENCES stilbite cannot coexist in equilibrium except at one fixed temperature, which represents a transition point. Although heulandite might very well persist in an unaltered form beyond this point, it should never be deposited from solution simultaneously with stilbite. The replacement of chabazite, heulandite and stilbite by natrolite seems to have been effected with great ease, natrolite needles shooting out across areas of the three'lime zeolites as if no obstacle were offered. The manner of growth as regards chabazite and stilbite appears in 121 and is illustrated in figs. 26 and 28. In the hand specimen, a polished face was prepared, and it could be seen that the chabazite and stilbite were filled with slender filaments of natrolite radiating from a large area at one Fig. 27. Phantom crystals of some replaced mineral (probably chabazite) found as inclusions in stilbite. which extends uuiuterruptedly across the areas. X 35. Slide 110. In the microscopic section, the effects are similar. The slender needles of natrolite cross areas of the older minerals and also work in along joints of chabazite. A similar replacement of stilbite by natrolite appears in 71 and of heulandite by natrolite in 70. These two are from the same rock. In both cases, crystals of the earlier minerals have become isolated in masses of natrolite. The characteristic outlines have been lost, and the borders are so impregnated with natrolite fibres that one mineral seems to fade into the other. In 84, the hand specimen consists largely of dense white natrolite, in which small pinkish areas have a geometrical appearance and suggest that some mineral has been replaced. In the thin section, several of these areas appear. It is seen that the pink color is due to separated grains of. Please note that these images are extracted from scanned page images that may have been digit
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Keywords: ., bookcentury1800, bookdecade1870, booksubjectscience, bookyear1879
