~ RARE OPALIZED WOOD ~

What Is Opalized Wood?

Opalized wood is a type of petrified wood that is composed of opal rather than chalcedony or another mineral material. It almost always consists of common opal, without play-of-color, but rare instances of petrified wood composed of precious opal are known.

Opalized Wood Cabochon
Opalized Wood: A cabochon made from opalized wood from eastern Oregon. This cabochon measures approximately 11.5 x 17 millimeters and weighs 5.35 carats. GIA Lab Report for this stone.

How Does Opalized Wood 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.

Large deposits of petrified wood in Arizona, Oregon, Wyoming, Indonesia, Russia, Mexico, Brazil, and other parts of the world have formed in this environment.

In most situations, the petrified wood found in these deposits today is composed of chalcedony, but in some situations the wood is composed of opal. Both of these varieties of petrified wood often occur in a single deposit.

Because they are both formed from dissolved silica, they are often called "silicified wood".