Ammonites come from an extinct group of marine animals referred to as Ammonoids. The name was derived from the greek word for horn, because the spiraling shape of the mollusk resembled the coiled horn of a ram and Egyptian goddess Ammon who was commonly depicted wearing horns. Fossils from this family of mollusk date back 416 million years, and are believed to have gone extinct around the same period as dinosaurs, they can range in sizes from less than an inch to more than 9 feet wide! These fossils are composed of the calcium carbonate called calcite, mineral deposits of silica or iron sulfide fill the shells over time causing silification or pyritization, some even have an opalescent sheen. Ammonites are believed to keep us in harmony with the universe, their sacred geometry patterns stimulate the constant circulation of energy and can be used for feng shui. They are also believed to embody ancient knowledge and wisdom, they can be used to promote fertility, or the bring about prosperity and growth.