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Bonsall Tonalite
Field Collector: Esper Signius Larsen Jr.
Place Collected:Near Banning, CA, San Jacinto Quadrangle
Object number: ROC21703
DescriptionPlutonic, medium-grained (1-5 mm) igneous rock that is salt and pepper on a fresh surface. Consists of 65% white plagioclase (2-6 mm), 25% light grey quartz (1-4 mm), 5% black biotite (≤2 mm), and <5% K-feldspar (<1 mm).
In Collection(s)