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Ig. Home | Simp.Class. | Advanc.Class. | Alpha.List | Bowen's Reac.Srs. | ID Keys | Extrus/Intrus | Tect. | Self Tests ALKALI GRANITE   (detail)

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Another specimen

  Return to Classification; pdf version Typical Minerals QUARTZ > 20%
ORTHOCLASE is greater than
Mafics - < 10% Detail Description      In this detail the pinkish colored orthoclase stands out clearly, but quartz is also common (clear, glassy, no cleavage; for example the grain on the bottom, just left of center.)
     Mafic (black)minerals are rare (<10%) in granites. The mafic mineral is most likely biotite with a few grains of amphibole too.    Return to Whole Image
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