The quartrefoil shape is defined as "four leaves" and has been used as a decorative and symbolic motif for centuries. Most associated with Gothic and Renaissance architecture, the quaterfoil has seen a resurgence in popularity. Here are a few instances that I particularly like:
1. Quatrefoil Headboard from Horchow
2. Paul Morelli Pearl & Diamond Quatrefoil Earclips
3. Quatrefoil Wallpaper from Seabrook
4. DIY Upcycled Quatrefoil Dresser from Kreative Knack