A substantial split ammonite from Madagascar, cut and polished to reveal an exceptionally detailed interior filled with warm amber, cream, olive, and rust-toned mineralization.

Measuring just over 6" × 5", this matched pair preserves the ammonite's tightly coiled internal structure in beautiful detail. Thin, pale septa trace the boundaries of dozens of individual chambers, many of which have been partially or completely filled with crystalline mineral deposits during fossilization. Several small open pockets retain visible crystal growth, adding texture and depth across the polished faces.

Particularly striking are the scattered metallic areas visible throughout the specimen. Pyrite mineralization is known to occur in polished ammonites from Madagascar, including within and alongside their mineral-filled chambers; the metallic material in this specimen has not been independently tested and is therefore described conservatively as possible pyrite.

Ammonites were marine cephalopods related to modern squid and octopuses. As the animal grew, it continually added new chambers to its shell, producing the intricate segmented spiral exposed here. Madagascar specimens of this general type are typically Early Cretaceous in age, approximately 110 million years old.

Both halves originate from the same ammonite and together weigh nearly 800 grams, giving the pair considerable presence as a display fossil. The combination of large size, crystalline chambers, varied natural coloration, and flashes of metallic mineralization makes this an especially attractive example for a fossil collection, curiosity cabinet, office, or library.

Details Specimen: Ammonite Size: Approximately 6" × 5" each half Total weight: Approximately 795 g (390 g + 405 g) Locality: Madagascar Two polished halves of a single ammonite Crystal and mineral-filled internal chambers Metallic mineralization present; possibly pyrite Natural open crystal pockets One-of-a-kind fossil specimen

You will receive the exact ammonite pair pictured.