Petrified Wood Bookends (Arizona) 507ab8d06fe18ca7f56c6d954b848ca3 feeding upon plankton by a

feeding upon plankton by a simple yet efficient filtering system

aqua marina meaning "water of the sea" in Latin

fossils sites preserving them are generally restricted to Lagerstätten

and the only one suitable for faceting as a gemstone

the amount of Neanderthal at any given time was remarkably small

Petrified Wood Bookends (Arizona) 507ab8d06fe18ca7f56c6d954b848ca3 feeding upon plankton by aFrom 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