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Trachyte Igneous Rock
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Trachyte Igneous Rock. Typically white to light gray, extrusive rock. Major minerals include feldspar and biotite mica. Trachyte has a porphyritic texture which is mostly fine-grained with many large grains visible. Each rock sample is approximately 1-2 inches in length and width. An information card with details on the rocks formation, mineral content, characteristics and uses is included.