Andesite is a grey, igneous rock with fine-grained (too small to be seen) interlocking crystals. The specimen shown contains larger crystals which crystallised more slowly at an earlier stage.
Locality - Stewart Peak, Southwestern Colorado
© share alike, taken by Joel Parham
Hand specimen |
Locality |
Rock in use |
Close-up |
Thin section p-polars |
Thin section x-polars |