Blac Chyna reportedly returned her 7-carat engagement ring to Rob Kardashian after an argument last month, E! News reported. Blac Chyna was photographed without her diamond ring as she departed the TAO Hollywood nightclub on Tuesday."Chyna and Rob are certainly not together or engaged," a source told E! News. "In fact, Chyna gave the engagement ring back to Rob when they broke up last month ... Something caused them to have a blowout fight, and Chyna gave the ring back and it was done. They officially are not engaged. There is no wedding."