Button?

Is this a button?   How old do you think it is?

Does it look like a small chain link going through the opening? It might be a cuff link but I'm not sure

Does it look like a small chain link going through the opening? It might be a cuff link but I'm not sure

The small hole in the back does not go all the way through. The metal backing is snapped off. 

I'd guess cufflink, too.

It's probably just some sort of fanciful abstract design, but the whorled pattern sort of reminds me of "fingerprint" or "thumbprint" cufflinks, like this one:

I agree Cuff link. Thank you.