Andesitec Andesite has a dark gray-blue color.

andesite_2_zach_zoske.jpgAndesite_full_size_landscape.pngandesite_zach_zoske.jpg Andesite is an igneous, fine-grained Extrusive rock.Andesite forms at convergent plate margins and is thought to be the product of partial melts of the water-rich subducting oceanic crustal basalts or of the intervening wedge of lower crustal rocks above the subducting plate.
Igneous rock formation image courtesy of Rock Hounds
Igneous rock formation image courtesy of Rock Hounds
Andesite is used mainly for making tiles, bricks, or stones that are suitable for water or landscape gardens.
andesite_brick_zach_zoske.jpg

Some minerals commonly found in Andesite are, Biotite, Quartz, Magnetite, and Sphene. Sometimes Alkali Feldspar can also be found in Andesite.