The 24-year-old 'Rolling In The Deep' singer, who has kept her baby boy's name a secret since his birth last October, was spotted wearing the gold necklace in Los Angeles, reported Sun online.
Adele is engaged to charity worker Simon Konecki.
"Those close to Adele have been told the baby is called Angelo. We're not sure of the significance of the name. She's wanted to keep it quiet but it was always going to come out sooner or later," a source said.
"Wearing an Angelo necklace not only backs up what is being said, it suggests she's not worried about people finding out," the source added.
Adele refused to reveal her first child's name at the Golden Globes, where she made her first formal public appearance since giving birth to her baby.
She picked up the Best Song prize for her theme to James Bond film "Skyfall" at the ceremony earlier this month but did not reveal the name because she was 'not ready'.