Serotonin is the molecule that makes us feel pleasantly happy, relaxed, and satisfied. It's the feeling of lying on a Caribbean beach on a sunny day. It's also the peace of feeling satisfied with one's life and one's self.
http://www.giftsandrelationship.com/what-to-give-girlfriend-for-christmas/ The jewelry is cute Christmas gift for girlfriend and she will be definitely happy. Through a chain, a bracelet, a ring or earrings she will always remember you.