Gold pendant necklace with ruby charm

I lost my gold 14k pendant necklace yesterday around 3pm near Union Square Park on 14th Street in NYC. It's a 16-inch gold chain with a heart-shaped ruby pendant that catches the light. The back has a tiny etched 'M', and the clasp shows a small scratch from a fall a few weeks ago. It's unbranded but looks elegant, and it was a meaningful gift from my grandmother, so I really need it back.