Polished ammonite half, Madagascar

A genuine fossil ammonite from Madagascar, cut and polished to show off its chambered internal structure.  It is discreetly and permanently attached to a clear plastic base.  

Ammonites are extinct relatives of modern day nautiloids and squid. The largest known ammonite in the world would have been 8 1/2 feet (2.59 metres) across if it were complete.

3/4 inch (1.9 cm) wide, 3/8 inch (0.95 cm) deep and 9/16 inch (1.4 cm) tall.