Marcasite and Silver Floral Vase Brooch

Excellent quality in this silver brooch marked sterling and JJ to the back.  From an estate sale USA, research has not shown up the exact signature so unsure as to the exact maker - there are more than one possibility, The silver is weighty and perfect with a firm roll over safety clasp to the back. The four coloured rhinestones are shiny and bright and the silver brooch presents as new. Overall dimension is 4cms x 5cms.