9ct Gold Pearl and Ruby Stud EarringPearl and Ruby Studs These 9ct yellow gold stud earrings are set with a classic combination of cultured pearls and rubies. Each earring centres on a lustrous cultured pearl, which is complemented by a single, round cut ruby. The warm 9ct yellow gold setting, containing 37. 5% pure gold, provides a durable and traditional foundation for the gemstones.