The calyx and stamens on the inside (which you can’t see unless you peer inside) is sterling silver. The peacock feathers are glued in.
The cornflower is approximately 43mm. Including the bail it measures approximately 60mm.
The calyx is 9mm wide at the widest point.
This pendant comes with a 30 inch (77cm) sterling silver chain. Adele recommends wearing this as a long pendant so the feathers don’t rub against skin oils and sunscreen oils. The oils seems to make the feathers turn towards a greener colour.