The blonde beauty and new mum collaborated with longtime friend Laurie Lynn Stark, who owns Los Angeles-based jewellery brand Chrome Hearts, on a new collection called CH+KH.
The Almost Famous star tells fashion publication Elle magazine, ""It occurred to us, we spend all of this time together - why don't we make something?""
And the pair did just just that.
Stark adds, ""We used a lot of aquamarines because Kate loves them, but, to me, they also evoke her personality. She's so open and light.""
The bohemian-inspired, ultra-feminine pieces can be purchased at select Chrome Heart boutiques.