Product Overview
Andesite features abundant phenocrysts in a fine grained matrix, and offers a great demonstration of igneous porphyry. Ideal for identification & classification exercises. Andesite is an excellent example of porphyry in igneous rocks. The fine-grained felsic matrix contains larger, identifiable hornblende crystals, indicating two different rates of cooling. While each specimen will vary slightly in shape, size and color, it will measure approximately 3" in length. Each is individually packaged, labeled & barcoded for easy identification and storage.