Ig. Home | Simp.Class. | Advanc.Class. | Alpha.List | Bowen's Reac.Srs. | ID Keys | Extrus/Intrus | Tect. | Self Tests |
PLAGIOGRANITE (detail) |
Return to Whole Image A More Detailed Look Return to Classification; pdf version |
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.) 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. |
Return to Whole Image; pdf version Return to Classification |
Last Update: 9/29/00 | e-mail: (Fichtels@jmu.edu) |