1076/1980
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Government Mountain Obsidian

governmentmtobsidian.jpg Galena, Alternate ViewThumbnailsKaibab Chert

Description: Government Mountain obsidian comes from the slopes of Government Mountain in the San Francisco Volcano Field near Flagstaff, Arizona. The material is fine-grained and generally lacking phenocrysts, but appears granular because of the presence of alkali feldspar in the matrix.