Item appears to be bronzed coconut tempurung half, measuring 8 centimeters in diameter. I say “appears”, because the item seems to be made completely out of bronze, but with the thickness of a real coconut shell. No other decoration or design anywhere else, apart from what you normally expect from a real coconut shell.
UPDATE: Microscopic analysis results have come back: turns out that the coconut shell resembles a coconut shell, even down to the microscopic level — we’re seeing remnants of cell wall formation on at least part of the coconut shell, which either means that the bronzing process goes down to the cellular level, or there’s a species of bronze-based life form out there. Alloy composition is around 88% copper and just under 12% tin, with less than %1 being a material that should be tin, but doesn’t seem to give the same kind of spectral readings.
An interesting effect occurs when you place the coconut shell, rim-side down on any flat surface — within 20 seconds, the sound of a frog croaking can be heard. Our resident creepy-crawly nerd identifies the call as belonging to a Polypedates leucomystax, or a Malaysian common tree frog.
Removing the coconut shell reveals… well, nothing. No frog. Frog calls immediately terminate upon removal of shell from the flat surface. Even tipping the shell to take a peek reveals no frog, and terminates the sounds.
UPDATE: We’ve finally managed to take a good luck at the frog itself by the simple expedient of placing the shell on a glass table. Well, it’s a common tree frog, all right.
That’s it. Well, that was exciting.