Cufflinks by Josef Koppmann Stunning 24ct gold, silver and antique tourmaline cufflinks. The cufflinks are handmade using sterling silver. The tourmaline is set into solid 24 carat gold and a hinged bar, soldered on the back of the square, snaps securely into place when worn. Features Primary Material : 24ct gold and sterling silver Fitting Type : hinged bar Dimensions (mm) : 13x13x3 One of a Kind : Yes Metal : 24ct gold and sterling silver Gems : antique tourmaline Hallmarked : Yes Cleaning InstructionsThe cufflinks are best kept clean by rubbing and brushing them gently under running water with bicarbonate of soda. Do not submerge in water for long periods and do not clean the cufflinks in ultrasonic cleaning systems.