The singer splashed out the huge sum on a pair of Montblanc diamond earrings and a bespoke diamond Chanel J12 watch and presented them to the 27-year-old actress before the Metropolitan Museum of Art Costume Institute Gala in New York on Monday .
A source said: "Justin splashed out on the trinkets to show his devotion."
Jessica was reportedly upset with the 28-year-old pop heartthrob's steamy antics with Ciara, 23, in the music video for the pair's song
Love Sex Magic
Justin was co-hosting the exclusive event with fashion designer Marc Jacobs, supermodel Kate Moss and US Vogue editor Anna Wintour.
Tables at the gala cost an average of $120,000. Former Spice Girl Victoria Beckham was another star who spent a fortune on the event.
Despite feeling unwell, the 35-year-old star attended the ball wearing a custom-made Marc Jacobs gown, complete with a 4ft train.
A source said: "Victoria really wasn't feeling well but she'd promised Marc she'd be there and as he'd made her dress, she really couldn't let him down."
The former Spice Girl was seated on the same table as
star Madonna and her Brazilian boyfriend Jesus Luz.
Other guests included actress Kate Hudson, supermodel Helena Christensen, British model Agyness Dean, pop star Rihanna and actresses Eva Longoria Parker and Renee Zellweger.