petrified wood

apache arizona ash bark buried carbon cells cellulose chromium cobalt colorful coniferous copper crystals decomposes decomposition desert enormous eroded forest fossils inhibits iron laden log manganese materials mineral minerals national navajo opal organic oxides oxygen park petrifaction petrified preserved quartz rare rings sediment semi silicate southwest states steppe stone structures terrestrial the three tree trees triassic underground united vegetation vibrant volcanic volcanoes western wood woody