Conk Opal from Virgin Valley District of Nevada USA

Slab of the ultra rare, precious opalized wood (Opal replacing wood) known as "Conk" Opal from the Virgin Valley of northwestern Nevada USA. Conk is a type of wood where part of the wood was eaten by a fungus. The wood was buried in volcanic ash layers and part of the rot cells were replaced by precious Opal over about 15 million years. Christopher Wentzell Trust collection.