A top quality 13x11" slice of petrified wood collected near Ambilobe, Madagascar.  This 220 million year old fossilized wood comes from the Araucaria tree, a type of prehistoric conifer.  The rich colors are due to mineral impurities in the silica which replaced the original wood material during the fossilization process.  For example red coloration is due to iron based compounds.  The tree rings and wood grain are still visible when the petrified wood is cut and polished.  

One of several large petrified wood slabs just added for sale at Fossil Era.