Thank you for submitting your item for appraisal. This appears to be a late victorian or early edwardian ca. 1900 hand painted porcelain brooch, gilt metal mounted. The cobalt blue surrounded portrait of a young lady might have been inspired by the Portrait of Georgiana, Duchess of Devonshire by British artist Thomas Gainsborough. The estimate is based on similar offered or sold at auction. There is no measurement for the sentimental value you might attacht to the item.