I chanced upon these valves of a Tridacna gigas in the garden of a local hospice I was visiting today. My initial thought was that they were perhaps concrete imitations. But a closer look revealed all the defects, the buildup and the growth rings one would expect on a real clam shell.
How often does one just find giant clam valves tucked away in the corner of a garden somewhere far away from the ocean unless one is dreaming? And I wasn't dreaming. But life is full of surprises.