Petrified Wood

Petrified wood is fossil wood in three dimensions: the remains of trees and tree-like plants whose tissue has been replaced by stone through mineralisation, sometimes keeping the original structure of the stem. Its formal name is unsettled because no single mineral makes it up: Wikipedia says the replacing minerals are mostly silica in the form of opal, chalcedony or quartz, and Cunningham says only that the wood was replaced by various minerals. Unlike most plant fossils, which survive as flattened impressions or compressions, it preserves the whole shape of the original wood. Cunningham calls it receptive, a fossil millions of years old, and explains it as ancient trees covered by mineral-rich water that slowly dissolved the wood and left minerals in its place. Its great age, he writes, is why it is carried or used in spells to lengthen life, or to deepen enjoyment of and growth within the life one has, and why it is used to recall past lives. It is carried as a protective amulet for its hardness and strange appearance; once thought to frighten evil away, it is now seen as raising barriers of energy that turn negativity aside. He also records it carried as a charm against drowning.