Hello, sorry if this is a bit of a silly question, but please humour me.

I've been asked to repair a bangle by a friend-of-a-friend (I'm sure you all get this too). I'm not certain if it's solid silver, or silver plated. It does have a hallmark on the inside, but it's not British, and i'm not sure what it means.

I should probably be able to tell by looking at it, but alas, I'm not that clever. How to I find out if it's solid and can be soldered? I've filed a little bit on the inside and it remains a silver colour. Does this mean it's solid?

Sorry for asking a probably obvious question, but I'm afraid to heat this bangle without being certain in case I ruin it.

thanks!