A petrified organic substance (or the imprint of a fossilized plant or animal), the organic material having decomposed and been replaced over centuries by an inorganic mineral. Fossilized plantsproduce bogwood and jet. Fossilized materials are found in fossilized agate, jasper, and opal.Several varieties of fossilized animal life have been incorporated into articles of jewelry, including opalized snails and mussels, ammonite (shell of snail-like molluscs), turrilite (shell of aspiral-turreted mollusc), and lumachella (shell of triton-like mollusc).
Fossil

Fossil
A petrified organic substance (or the imprint of a fossilized plant or animal), the organic material having decomposed and been replaced over centuries by an inorganic mineral. Fossilized plantsproduce bogwood and jet. Fossilized materials are found in fossilized agate, jasper, and opal.Several varieties of fossilized animal life have been incorporated into articles of jewelry, including opalized snails and mussels, ammonite (shell of snail-like molluscs), turrilite (shell of aspiral-turreted mollusc), and lumachella (shell of triton-like mollusc).
References
From: An Illustrated Dictionary of Jewelry, autor: Harold Newman, publishers: Thames and Hudson



