In Victorian times, people sometimes gave their love or their close friend a mizpah ring or pendant to symbolize their steadfast love or friendship. When they were apart, it would be a reminder and comfort to the person wearing it.
The word mizpah is also sometimes found in cemeteries, particularly on tombstones honoring a deceased loved one. It's a Hebrew word from the biblical story of Jacob and his father-in-law, Laban. Jacob was leaving to go home with his two wives (Laban's daughters), and Laban named the spot where they parted Mizpah, or "watchtower." He said, "May the Lord keep watch between you and me" — meaning that since God was watching, Laban would remain loyal to Jacob, and Jacob would be careful to treat Laban's daughters well.