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ALKALI GRANITE (PEGMATITE) (detail) |
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Typical Minerals QUARTZ > 20% ORTHOCLASE is greater than Plagioclase Mafics - < 10% |
Detail Description
In this detail the pinkish colored orthoclase stands out clearly, but the quartz is not so obvious. It shows up as the darker gray patches. What is more obvious here is muscovite; a "book" of it can be seen almost on end (looking down the basal cleavages) in the upper left. |
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Last Update: 9/29/00 | e-mail: (Fichtels@jmu.edu) |