Large Victorian Scottish Silver Citrine and Pebble brooch, superb knot & sash

This is a very pretty large hand made silver Scottish brooch which is in a stylish knot & sash pattern with Citrine central stone and cut and shaped agate in the body of the main sections of the brooch. Size:approx: 52 mm across. Please look at the images closely as they represent an important part of the description, thanks.