How do I find out how much a bracelet is worth...

[beansmum]

without having to traipse into town to a jeweller?

How do I even find out exactly what it's made of?

I think any expert wuold need to handle it to make an assessment so I think you'll have to traipse. You might get a nice surprise though. What do you think it's made of? And does it say 'cartier, 'tiffany'' or 'faberge' anywhere on it That would be a hopeful sign!

I think it's gold. It was a 18th birthday present from a relative so probably not worth £1000s but £100s I guess. I feel terrible wanting to sell it but I don't like yellow gold, and have never worn it.

If it's gold then it will have a value as the raw weight as well as whatever it's value is as an object iyswim. Hope you get good news.