Basalt
Photos
wellerr@cochise.edu
copyright 2011
basalt, oxidized scoria-1
When exposed to a warm, humid environment, the
iron minerals in basalt oxidize
to a red color (hematite).

basalt
49a
Photo is copyright free for
non-commercial educational uses.
Just credit photo to R.Weller/Cochise College.
Specimen courtesy of Dave Dechant