Another Irishman, by the name of O’Conner proposed to his girl on St. Patrick’s Day. He gave her a huge ring with a synthetic diamond.  

The excited young lass hurried home and showed it to her father, a jeweler. He took one look at it and had to break the bad news to her – it wasn’t real.

The young lass on learning it wasn’t real, returned to her future husband. She protested vehemently about his cheapness. “Seamus, how could you? And knowing full well that me own da is a jeweler!”

“It was in honor of St. Patrick’s Day,” he smiled. “I gave you a sham-rock, darlin’.”