Hi,
We've got a quite big (diameter: 4,5cm) silver brooch that has been passed on through our family since at least the early 19th century. There are no hallmark to be found anywhere on the brooch.
(the images are quite big. Therefore I just post links to them)
http://i55.tinypic.com/dzt7q8.jpg
http://i56.tinypic.com/jkuko4.jpg
http://i55.tinypic.com/11aa8w2.jpg
http://i54.tinypic.com/28s81n8.jpg
By the way, we live in Sweden, but we're not sure that the brooch itself is swedish.
If you have any questions about it just ask. But I can't promise that I'll be able to answer your questions as I don't know very much of this brooch.