Sediqi stashed the brown bag in the front, where it remained as he took his Checker cab to the car wash, drove a passenger to Long Beach and met a fellow cabbie for lunch Wednesday.
As he walked off to the restroom, Sediqi asked his friend to check the bag for identification.
"Oh, God," Sediqi, 40, recalled his friend saying as he stared into the bag. "Look at those things."
Inside, packed in clear plastic cases were diamonds - about 100 of them, cut and polished and worth, it turned out, $350,000. Also inside was a cell phone bill.
Sediqi, a father of two with a pregnant wife, called the number, trying to sound nonchalant.
"Um, did you leave anything?" the Afghan immigrant asked the man who answered, according to the Los Angeles Times.
"Oh, my God," the voice on the phone responded, according to a story in Friday's newspaper.
Sediqi arranged to meet the man, identified as Eric Austein, who had not yet departed LAX for New York, at the airport police station.
Police inventoried the diamonds and confirmed Austein's identity. Austein calmly took possession of the gems, hugged Sediqi and promised him a reward.
Sediqi said keeping the loot never entered his mind, even though his wife loves diamonds and he dreams of opening a restaurant.
"God is up there," he said Thursday as he waited outside an auto shop, where his cab was having its brakes fixed. "He always watches."