Kate was very fond of statement earrings during her twenties. Here is one pair she wore several times.
The earrings look like kites to me: a main base at the top followed by long thin chains draping down alongside the face. They move quite easily and do not appear to be stiff. The ends of the chains carry small metal discs. The earrings hang from a French hook.
Here they are on Kate:
In 2006 at an event.
Heading to work in December 2006.
In December 2006 at a club.