1886 Queen Victoria shilling

[Coin#addict]

I received this in a joblot. Weight 6 grams and 23.5mm dimension. What would cause this mark on it?

Thank you. 

[mrbadexample]

My guess would be that it's a detector find.

[declan03]

Yes bud it was in beside some detecting finds i bought. I just thought it would be silver all the way through. It looks like the silvering has come off in a thin layer.

[mrbadexample]

24 minutes ago, declan03 said:

Yes bud it was in beside some detecting finds i bought. I just thought it would be silver all the way through. It looks like the silvering has come off in a thin layer.

Will still be silver under the black bit.