Gold-tone necklace with pearl charm

I lost my gold-tone necklace with a small freshwater pearl charm yesterday around 3pm near the Brainerd Public Library on Willow Street. It's an 18-inch gold-tone chain with a lobster clasp and a 6mm pearl pendant; no visible brand mark. The back of the pendant has a tiny engraving 'MP' that I had added as a sentimental touch. The necklace was a gift from my grandmother and means a lot to me; I’d really appreciate it if someone found it and could return it. If you found it, you can email me at [email protected].