This is a very rare necklace as it's made from 20 million year old petrified wood from Indonesia. I have combined with with blue jade on a sterling silver chain with some substance as the necklace is adjustable to 23" by attaching the clasp anywhere along the chain. A Jade briolette is dangling from the back.
How was this formed?
Indonesia is a volcanic island chain that is currently active and this volcanic activity produces a wide array of unusual minerals and rocks. When wood is buried by volcanic ash and silica is mobilized from the ash, the silica will penetrate into the wood and replace the grains of the wood. Opal is a hydrated silica.
This is a one of a kind piece and a rare material.