Well preserved split pair is 5 inches wide that show great color and show detailed chambers.
Madagascar is known for beautifully preserved fossils from both the Jurassic and the Cretaceous periods. Many of them have been turned into agate, and the inner parts are often preserved as hollow spaces lined with crystals. They are beautiful when cut and polished to reveal this inner chamber detail and color.
These were not as common in the ancient tropical sea around Madagascar. And this This Polished Fossil Nautilus was one of them. Madagascar during the Cretaceous period was under a warm shallow salt water sea. Because the sea was so full of these animals they can still be found today. But the condition is key to the look of them. In this case this Nautilus was preserved quickly with minerals so that when it is cut open the beauty shines through. They normally have shades of brown and other colors.
Nautilus are cephalopods related to modern day Octopus and squid and they were common in the oceans. This Polished Fossil Nautilus had a round and hard shell that protected the creature. Today Octopus and squid have no shell but in the past they did. This Polished Fossil Nautilus has chambers that are now filled with minerals.
Nautilus were born with small shells but as they grew they would add a new chamber. The animal lived in the last chamber. As they fossilized the chambers filled with minerals. Because of the minerals the Nautilus display a wide variety of colors.