This must be a coin. It's made out of silver and it has an intricate design on it to stop dishonest Earthlings filing bits of the precious metal off it.

Yes it's a coin. This one's from America. We can put an exact date on it too - 1836.

This is a rare coin because the design was rejected and was never used which makes it more valuable than an ordinary one. The Americans call their coins dollars.

Why are they called dollars?

Well, English colonists in America used the word to refer to Spanish pieces of eight and the word was adopted by the USA in 1785 when their currency was set up.

The word itself comes from the German daler or thaler, a large silver coin used in the German States a couple of hundred years ago.