Big specimen of petrified wood, a type of fossil where organic wood material has been replaced by minerals, typically silica in the form of chalcedony or agate. The fine, parallel lines visible in the darker section are characteristic of preserved wood grain. Potential Varieties: Based on visual characteristics, it shares similarities with root beer variety common opal or "root beer" calcite. Similar specimens are often found in Oregon, Arizona, and Montana. Dimensions are 5" wide and 3" tall. Heavy.