Show sample as: 72-frame QuickTime VR or 360-frame QuickTime movie loop.    My periodic table poster is now available! Large Petrified Wood. This is a large, heavy piece of petrified wood. I'm listing it under copper because it's greenish in color, which usually indicates copper content. There's probably more silica and calcium than copper, but you could say that about nearly any rock. Source: Rockome Gardens Contributor: Theodore Gray Acquired: 29 January, 2009 Text Updated: 29 January, 2009 Price: $10 Size: 10" Composition: Cu