Gold-tone pendant necklace with heart charm

I lost my gold-tone pendant necklace yesterday around 3pm near La Plaza Mall's main entrance on 10th Street in McAllen. It's a slim 18-inch gold-tone box chain with a small heart pendant about 0.8 inches wide. The heart has a tiny blue gemstone in the center and the back is engraved with the initial 'L'. The chain shows minor wear, but the piece is otherwise in good condition. This necklace means a lot to me - it was a gift from my grandmother and I wore it daily. If anyone found it, I'd really appreciate getting it back.