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GABBRO   (detail)

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Typical Minerals
Ca PLAGIOCLASE & MAFICS (pyroxene) about 50/50

Amphibole often present
Olivine - absent to trace
Detail Description
     In this detail the pyroxene appears as black, somewhat elongate crystals. The calcium plagioclase crystals are both the dark gray masses and the white crystals (indicating plagioclases of different compositions, the result of fractionation during crystallization). This sample is from the Palisades sill across the Hudson river from New York City. .
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