Ammonite and Agate NecklaceThis Ammonite and Agate Necklace pairs a fossil from ancient oceans with a beautifully banded mineral formed deep within the Earth. The design features a fossilized ammonite alongside polished agate, both set in sterling silver. Ammonites were marine mollusks that lived during the Mesozoic era, and their spiral shells were preserved through fossilization over millions of years. Agate, a microcrystalline quartz, forms when silica rich fluids slowly