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Another specimen
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| Ig. Home | Simp.Class. | Advanc.Class. | Alpha.List | Bowen's Reac.Srs. | ID Keys | Extrus/Intrus | Tect. | Self Tests |
| PLAGIOGRANITE (greater detail yet)
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Return to Whole Image Another specimen Return to Classification; pdf version
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Typical Minerals QUARTZ > 20% PLAGIOCLASE is greater than Orthoclase (may be absent all together) Mafics - < 10% |
Detail Description
In this greater detail we see the mixed clear to translucent light colored sodium plagioclase and quartz (still hard to separate in a photograph but appearing gray, clear, glassy, instead of white.) Orthoclase is notably absent. The mafic (black) minerals are still not easily identified even under this magnification. We need to be able to rotate the specimen under a microscope looking for the cleavages to be sure of identification, but they are mostly amphibole. |
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| Last Update: 9/29/00 | e-mail: (Fichtels@jmu.edu) |