1 7/8 inches round. Stamped JBJ 925 S
Thank you for contacting Mearto with your appraisal inquiry.
It is a beautiful brooch with filligranwork. Such vintage brooches are being offered at auction on a regular basis.
The brooch is made of sterlingsilver and the design with the filigran work is very smart and classic. It was often seen on Norwegian folk dresses as the jewellery accessories. However it also became popular in the 1900s when your brooch was made - probably in the middle 1900s. This type was popular both in Europe and in the USA. I believe your brooch was made in the US.
The estimate provided is for a well-advertised specialised online silver jewellery auction, where I believe the brooch has the best chance of realising its fullest potential. However, there is no measurement for the sentimental value you might attach to the filigran brooch. Retail "asking prices" can be higher and vary.
Please let me know if you have any additional questions. I’m happy to help.