Kate was spotted wearing these earrings from Jigsaw when she was working for them in 2007.
Here is the closeup:
The earring appears to be a round silver disc flanked by two silver beads. It’s attached to a silver hoop which is then attached to a silver hook.
I haven’t found any information confirming that these are really Jigsaw’s earrings.
I have a sneaking suspicion that these might be Claudia Bradby earrings instead. The design and style of them (clunky and consisting of several components strung together) is more like Claudia Bradby’s signature style. I will email Claudia Bradby and ask if these are their earrings.
Update: Through Anna of My Small Obsessions, I have found out that Claudia Bradby did admit these were not her earrings. She said they do look very similar to some of her past collections, but they are definitely not hers.