Earlier today, Blac Chyna and Rob both posted pictures of her wearing a massive 7-carat diamond on her ring finger, announcing their engagement.The jeweler who made the ring, Ben Yang, also known as Ben Baller, posted a message to the couple as well . "Congrats to @RobKardashian& @BlacChyna on getting engaged. Rob, I have never seen you this happy before and I've known you since you were a teenager. I'm glad you came to your day 1 homie to get this massive [ring] for your lady. You know I don't play when it comes to diamonds. God bless #7Carats #VVS #IFANDCO #BlacChyna #RobKardashian."Another interesting connection is that Yang is also responsible for a number of pieces owned by Rob's brother-in-law, Kanye West. According to Pret-a-Reporter , the jeweler charges a minimum of $25,000 for each piece.Still no word from the rest of Rob's family, who are vacationing in Vail, Colorado.