(from the Greek root petro
meaning "rock" or "stone"; literally "wood turned into stone") is the name given to a special type of fossilized remains of terrestrial vegetation. It is the result of a tree or tree-like plants having completely transitioned to stone by the process of permineralization. All the organic materials
have been replaced with minerals (mostly a silicate, such as quartz),
while retaining the original structure of the stem tissue. Unlike other
types of fossils which are typically impressions or compressions,
petrified wood is a three-dimensional representation of the original
organic material. The petrifaction process occurs underground, when wood becomes buried under sediment or volcanic ash and is initially preserved due to a lack of oxygen
which inhibits aerobic decomposition. Mineral-laden water flowing
through the covering material deposits minerals in the plant's cells; as the plant's lignin and cellulose decay, a stone mold forms in its place. The organic matter needs to become petrified before it decomposes completely.
A forest where such material has petrified becomes known as a petrified forest
are the fossil shells of ancient squid. This animal lived in a
shallow sea which covered what is now the Sahara Desert in Morocco. It
is about 350 million years old.
This necklace has a lobster clasp and is adjustable from 17 Inches to 19 inches.