14k gold pendant necklace with heart charm

I lost my 14k gold pendant necklace yesterday around 3pm near Millennium Park, specifically near The Bean on Michigan Avenue. The chain is delicate, about 18 inches, and the heart-shaped pendant has a tiny sapphire set in the lower corner. On the back, there are initials 'M.R.' engraved. It was a gift from my grandmother, and it's really important to me—it's sentimental, and I miss it a lot. If someone happened to find it in the grassy seating area by the Crown Fountain or near the Lurie Garden entrance, please reach out.