Antique 9 ct gold Very large grand tour cameo brooch pin

A fantastic very large grand tour cameo which has been set into a later vintage 9ct gold mount with hallmarks for 1991. In very good condition. The line in the last but one picture is just the light reflection, there is a natural loss to one part of the shell to the reverse, seen in the last picture. This measures 9 cm x 7 cm 54.5 grams overall total approx