Hours after Osman Chowdhury, a native of Bangladesh, had dropped off the passenger, he tracked her down through a flurry of phone calls and returned the bag, which she had left in the taxi's trunk.
The unidentified woman, who said she was a jeweler, offered a $100 reward. Osman reluctantly accepted the money to cover the fares he lost while tracking her down.
Chowdhury told the Daily News that he never even thought of keeping the gems.
"I'm a hard worker," the soft-spoken cabbie said. "I enjoy my life. I'm satisfied. I'm not going to take someone else's money or property to make me rich. I don't want it that way."
"When I find something left in my cab and I can return it to the owner, I feel very happy. I feel proud," he said.