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The Epic Interactive Encyclopedia 1998
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Epic Interactive Encyclopedia, The - 1998 Edition (1998)(Epic Marketing).iso
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Feldspathoid
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1992-09-04
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424b
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13 lines
A feldspathoid is any of a group of silicate
minerals resembling feldspars but containing
less silica. Feldspathoids occur in igneous
rocks that have relatively high proportions
of sodium and potassium. Such rocks may also
contain alkali feldspar, but they do not
generally contain quartz because any free
silica would have combined with the
feldspathoid to produce more feldspar
instead.
Subject by: Robert Small