Abstract: A piece of jewelry having a copper-containing gold alloy consists of 58.5 to 58.7 wt. % gold, 26.9 to 32.6 wt. % copper, 5.7 to 10.7 wt. % silver, 1.0 to 3.0 wt. % palladium, and a remainder containing 0.7 to 2.2 wt. % zinc.

Abstract: A ring-shaped piece of jewelry has a metal main body, which forms a receiving opening, and an RFID transponder, in which data that can be read out are stored and which is connected to an antenna structure, by means of which antenna structure signals can be exchanged with a reading device. The RFID transponder is part of a transponder array having at least two additional RFID transponders, which extend peripherally on a peripheral surface of the metal main body, and the transponder array has a distance of 2 to 6 mm between two adjacent RFID transponders.

Abstract: A piece of jewelry has a copper-containing gold alloy which consists of 75.0 to 75.2 wt. % gold, 16.5 to 17.0 wt. % copper, 3.1 to 7.1 wt. % silver, 1.2 to 3.2 wt. % palladium, and a remainder containing 0.5 to 2.5 wt. % zinc.

Abstract: A ring-shaped piece of jewelry has a metal main body, which forms a receiving opening, and an RFID transponder, in which data that can be read out are stored and which is connected to an antenna structure, by means of which antenna structure signals can be exchanged with a reading device. The RFID transponder is part of a transponder array having at least two additional RFID transponders, which extend peripherally on a peripheral surface of the metal main body, and the transponder array has a distance of 2 to 6 mm between two adjacent RFID transponders.