Lost silver necklace with reddish agate pendant

I lost a very sweet necklace when I visited Chicago 3/22. I walked around Lincoln Park and Old Town all day so it could be anywhere. I last felt it while at the Lincoln park conservatory. From there I walked up Clarke and down Lincoln, Sedgwick and many side streets. I visited kook kook, kapeje coffee, and Cocoa and co.

The necklace has a silver chain. It has a round silver backed pendant. The pendant is a reddish orange agate with some thin white stripes toward the bottom.

It was a gift and it hurts to have lost it. I think the chain failed. Please let me know if you find it