Why does an "O" & an "X" mean "hug and kiss"? As is often the case, there are lots of different explanations and there's even some confusion as to whether the X or the O is the hug or the kiss!
Some say the X represents the crossed arms of a hug and the O a set of lips puckered up for a smooch. More commonly people use X to represent a kiss and O for a hug. Either way, Hug and Kiss, or Kiss and Hug rings and earrings say Love!
The Oxford English Dictionary states the first X recorded as a kiss in literature was in 1901. Prior to that X was used as a signature in times before most people could write. The X was a mark of one's word and after signing people would often kiss the X they had made as a seal of honesty; literally "signing with a kiss".
The origins of the O as a hug are not generally known although it may represent two arms held in a circle around another person just as the X may represent two sets of lips coming together.
The wonderful thing about these stories is that no matter what they may have meant to millions of other people before you, when you sign your next message to someone you love it will mean something very personal to you and the one you hug and kiss.