Grey Penguin Classics edition with lime bookmark

I lost a grey Penguin Classics edition of Brave New World yesterday around 3pm. It's a small paperback, part of the Printed Media category, about the size of my palm, with a lime-green bookmark sticking out between pages and a slightly creased spine; on the back cover there's a faint coffee stain. I think I had it after browsing the shelves at Cardiff Central Library, then wandered through The Hayes toward St. Mary Street. It means a lot to me—it's a gift from my grandmother and has sentimental value—and I’m really hoping to get it back. If anyone found it, please drop me a line here; I’ll come collect it from you as soon as possible.