Ammonite is a fossilized sea creature similar in structure to a snail. Pyritized ammonite is a rarer form of this fossil which adds the properties of pyrite to those of an ammonite fossil. See also Petrified Wood.

During the middle ages ammonites were called draconites due to the belief that they came from the heads of dragons. Another name, "snakestone," was popular among occult circles. In ancient Egypt, ammonites were seen as a symbol of any ancient deity who was associated with the ram and its curved horns, while in Ethiopia, they were sacred stones, worn to gain prophetic dreams and grant the wearer deep meditations. In England today, the ammonite is considered a stone of miracles. This is based on belief from the seventh century that, when St. Hilda prayed for the people's protection from the snake infested River Esk, the snakes coiled up and rolled off the cliffs, instantly turning to stone.

Ammonite eliminates any caustic personality traits and transforms negative energy into positive. Those in the fields of construction and architecture would find these stones particularly useful. Not only does ammonite provide insights into a creative problem, it also allows you to utilize the “whole picture” from the start to finish of a project. Ammonite is a protective stone, adding stability and structure to life, and it also enhances one’s survival instincts and abilities. Birthing and re-birthing processes find assistance with ammonite.