Opalized Wood

Opal is composed of hydrated silica. It is an amorphous silicate, meaning it does not form crystals. Opals are structurally composed of tiny spheres of silica which, when arranged in perfect geometry, create the famous play of color associated with the stones. The symmetrical arrangement of silica balls acts like a prism, which allows the rainbow spectrum of colors to be visible to the naked eye.

From ancient Greek meaning "wood turned into rock", Petrified Wood is a form of fossilization where all the organic matter combines with minerals (usually a silicate, such as quartz) during a process called per-mineralization. In order for wood to become petrified it must be completely covered by sediment, thereby depriving the wood of oxygen. Simultaneously, there must be a mineral rich water source close by. Over time, the water delivers the minerals into the cellular structure of the wood, replacing (and in most cases), combining with the organic material, cell by cell, until the wood is transformed into stone. Wood petrification is unusual in this way. If acid were used to dissolve into the stone, one would actually still find organic material. In regard to petrified wood colorization, each specimen is dependent upon other minerals present in the locality at the time of fossilization. Streaks of warm browns and reds are indicative of iron oxides intermixing with quartz and other minerals during a specimen's fossilization process.