Obvious with the caseback, the oscillating mass in the motion is delicately engraved. It is actually made out of 18-karat gold and decorated by hand which has a barley grain sample, performed by guilloche If the Omega has the words 'Master Chronometer' about the dial—as is noticed in the Seamaster https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/