Gold pendant necklace with small heart charm

I was strolling around Main Street Square in downtown Rapid City yesterday around 3pm when I realized my necklace was gone. It's an 18-inch gold-plated chain with a small heart pendant, about the size of a pea. The charm has a tiny engraving on the back that says 'Mom' and there's a faint scratch along the clasp. This necklace has sentimental value—it's a gift from my mom, and I really need to get it back. If you found it near Starbucks on Main Street or around Main Street Square, please message me.