Lost gold necklace with small heart pendant and delicate chain last seen at Millhouses Park in Sheffield.

I last remember having my gold necklace with a small heart pendant while I was picnicking at Millhouses Park in Sheffield on Saturday afternoon. I noticed it was missing when I got home and can't seem to find it anywhere. It has a delicate chain and means a lot to me, as it was a gift from my grandmother. If anyone finds it, please get in touch.