An unusual naturally black ammonite from Ancash, Peru, still backed by some matrix. This one is simply trimmed so that it stands securely on its own.
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.
1 1/8 inches (2.9 cm) wide, 9/16 inch (1.4 cm) deep and 7/8 inch (2.2 cm) tall.