Petrified Wood Reveals Gorgeous Rare Turquoise Opal Hiding Inside

How did it get this shape and color? According to Geology.com, volcanic ashfall is the ideal environment for opal and petrified wood to form. One of the most common and best geologic environments for the formation of petrified wood is a forest buried by a volcanic ashfall. In this situation the ash buries the plants and protects them from decay and insect attack. The ash also serves as an abundant source of easily dissolved silica, which will be carried into the wood by moving groundwater where it precipitates in cavities and replaces the solid woody materials, the website writes. This pure form of opal is absolutely beautiful and is a popular and expensive mineral that is often used in jewelry and works of art. The word 'opal' actually derives from the Greek word Opallios, which loosely translates to perceiving a change of color. When you shine light on an opal, it has the tendency to change color, making the whole thing even more spectacular.