Hans - that was my first thought. The top of the item looks charred and blackened.
When metals such as magnesium, potassium and calcium burn, they burn very hot and bright, and do not leave this kind of blackened char.
besides, those metals are expensive, and you'd never make this kind of item from them.
I thought it looks like a plastic moulding that has been painted in silver paint.
The definition of the moulding is quite poor, and most low-melting temperature metals would give a much sharper relief.
Tambo, can you see if the thing floats (or nearly floats) in water, as a plastic would float, whereas any metal would sink very quickly?
Hope it helps