Porphyritic Granite Dike

Porphyritic Granite Dike

SFM-24

Hand Sample: Phaneritic granite with coarse-grained phenocrysts of smokey quartz and generally smaller crystals including potassium feldspar. Weathers to orange on one side and some light-gray material on the other.

Thin Section: 25% coarse-grained quartz phenocrysts in a matrix of 40% fine-grained rectangular plagioclase laths, 30% fine-grained alkali feldspar, and 30% fine-grained quartz.

1/20/1969

Western Minerals, Inc.

St. Francois Mountains Batholith, Missouri

Purchased from Western Minerals, Inc.

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