Dating rumors have sparked since Rihanna and Chris Martin were spotted dining together. ... Or perhaps they are just planning another collaboration.

The pair was on their dinner date at the "Diamonds" hitmaker's favorite L.A. eatery Giorgio Baldi in Santa Monica on Sunday evening, June 8. Rihanna was sporting a vintage-inspired black-and-white top with three-fourths-length bell sleeves and a pair of jet-black skinny jeans. She completed her conservative, sophisticated ensemble with a pair of pointed-toe Christian Louboutin pumps and a petite Louis Vuitton monogram canvas purse. The Coldplay lead vocalist, who has gone through "conscious uncoupling" with wife Gwyneth Paltrow earlier this year, opted for a more casual, laid-back look.

The two music artists appeared to be enjoying each other's company, as the 26-year-old Rihanna was seen laughing and smiling throughout the meal and paying close attention to the 37-year-old singer when he was speaking to her. After dinner, the couple left the restaurant separately -- the Barbadian beauty was escorted to her car by security, and the British rocker made a private exit in his own car.

Rather than dating, Rihanna and Chris Martin may be coming up with a new collaboration. They famously worked together on "Princess of China" off Coldplay's last album "Mylo Xyloto" back in 2012. Also, the "What Now" singer previously joined the rock band on stage to perform the hit track at the 2012 London Paralympics as well as the 54th Grammy Awards. The duo have remained good friends for years since working together.

Meanwhile, it has been reported that Rihanna has completely moved on from Chris Brown, who recently was released from jail.

"Look, Chris is ancient where she's concerned," a source said. "They're not together and that chapter of her life has been long and gone. She don't hate the boy -- yeah, he's a boy -- but she doesn't hate him."

"As far as his being out of jail, I mean, congratulations I guess," the source said. "She certainly wants him to thrive and have a good life. She wishes him well but from a major distance."