Ammonite Cymatoceras (Madagascar) polished with stripes

This little gem from Madagascar is rare, and it required very special conditions for it to form: This nautilus type ammonite dates from the Albian (110 million years), it is a Cymatoceras sakavalum. On the seabed where he layed once dead, movements pushed the shell on rocks, and this pierced the shell in several places. It is by polishing the shell that we notice what happened inside: When a chamber is gray, it is that clay infiltrated through a hole and filled it. When a chamber is of caramel color, it is because Calcite was formed during the fossilization. And chance gave this alternating stripes that’s just perfect