Gold ring with emerald setting found in London

I found a gold ring today, probably 14k, with a small oval emerald center stone. The band is slim and well-polished, about a size 6.5, and there's a delicate vine engraving on the inside. I picked it up this afternoon around 4pm near Covent Garden, outside the Royal Opera House entrance and the street performers at Bow Street. The emerald has a vivid green glow, and there's a tiny nick on the side from what looks like wear. It clearly belongs to someone—it felt wrong to keep it—so I'm hoping to reunite it with its owner.