The eye-catching accessory in question is reportedly a gift from the rapper himself to represent "their special connection," E! Online reports.
"He got her that necklace because he felt that it represents a special meaning between both of them," a source says. "Arianna would always compliment him on his necklace and when he got it for her it was his special gift. She loved it!"
Romance rumors between the two hit a fever pitch in August, when they were caught by cameras holding hands backstage at the MTV Video Music Awards. In September, she admitted in an interview with Marie Claire that she got into a car accident on the way to his house.