Billionaire Facebook founder Mark Zuckerberg, 28, is getting a lot of flack for being cheap with his new bride. He married Priscilla Chan, 27, in a surprise ceremony in their backyard last Saturday and Chan wore an off-the-rack dress by Claire Pettibon. No fancy venue or Vera Wang gown for this bride! Experts consulted by the UK paper The Daily Mail are claiming Zuckerberg was too frugal and thoughtless because of the "very simple" ruby ring he gave Chan (the AP reported that he designed it himself). However, an expert consulted by Yahoo! Shine points out that rubies are extremely significant and popular in Asian culture, and can potentially be more expensive than diamonds. Celebrity rings and their knock-offs Thanks to Facebook going public, Zuckerberg is now worth over $20 billion (at least, he was before stock price started to fall), and though he's partial to wearing casual hoodies, he may still have bought his long-term girlfriend a nice ring. Chan was spotted showing off her new bling at lunch with a friend in Palo Alto, California on Wednesday, and while the jewelry designer and price of the ring remain undisclosed, a ruby expert told Yahoo! Shine exclusively that the ring could have cost over $100,000. "It's a small stone, but rubies can be extremely expensive," says Michael Arnstein, CEO of the Natural Sapphire Company. He estimates the size of Chan's ruby to be 2.75 to 3 carats. Rubies of that size cost from $20,000 for a low quality stone, to up to $100,000 for a higher quality one. "The value depends on the quality of the ruby, and it's hard to tell for sure from the photo," Arnstein says. "A Burmese ruby, which this definitely looks like, can cost upwards of $100,000." The two diamonds flanking the ruby look to be around 1 carat combined, and could tack an extra $5,000 on to the price tag. As for Zuckerberg's choice of a ruby, Arnstein is not surprised. "Red has more meaning and emotion in Asia," he says, and Zuckerberg's Chinese-American bride may have requested a ruby ring because it "identifies where she comes from culturally." Rubies are a symbol of wisdom--what better for the new medical school graduate? And, the jewelry expert points out that Zuckerberg and Chan are conservative, and the engagement ring isn't too flashy but rather something she'd feel comfortable wearing every day. Arnstein also says the setting appears to be yellow gold, which is also more traditional in Asian culture. "Zuckerberg loves her and would have bought her anything she wanted, but this is probably what her grandmother had."