Lost necklace with large purple stone and gold platted chain

[nonsensicalbubbles]

I lost my grandmother's necklace on 05/12/15 somewhere between London Bridge station and East Dulwich station around 16:30 - a gold coloured platted chain with a large purple stone. I've filled out a lost property form in the hope someone has picked it up. It's of sentimental value. Really hope someone has found it.