This would probably open, it has a seem running through it. I have seen other examples with pictures inside. I haven't opened it, for fear of breaking it. I'm not sure of metal content. It looks gold plated, but haven't tested it. It measures 23x30mm or about .75"x 1 1/4"It weighs 6 grams or .2ozs. 

Thank you for looking. See my other items.