EXCLUSIVEIf Mark Zuckerberg's new wife was expecting a MASSIVE diamond on her wedding ring ... she was SORELY disappointed.
Just days after the surprise wedding of the century, Priscilla Chan-Zuckerberg took her brand new ruby rock on the road ... flashing her piece during a lunch date with a friend in Palo Alto, CA yesterday.
According to reports, the $20 BILLION Facebook honcho -- who has a reputation for not caring about excessive displays of wealth -- designed the ring himself.
It's unclear how much the ring cost ... hopefully not much ... 'cause his Facebook stock has been sinking like Natalie Wood ever since it debuted on Friday.
So, we gotta ask ...