I've designed this pendant for my girlfriend's graduation. The base is the pendant, a sterling silver circle with the outline of a boat and a sunset. I've made 6 little disks that function as interchangable backgrounds, so the appearance can be changed depending on outfit or mood. It can also be worn without a background, for a more minimalistic look.
The system works with magnets, there are 5 1x1mm highly magnetic neodymium magnets glued into the backside of the pendant and the backgrounds are custom 3D printed with space for 5 0,5x1,5mm magnets each. The magnet system makes for a clean look, without fragile moving parts, but also causes the background disks to be easily changeable and always perfectly aligned. To complete the design, I've made a custom box, which has a completely flat inside surface, but due to underlying magnets, the pendant and the backgrounds are always aligned perfectly on it.
The pendant and the plastic background disks are drawn in SketchUp and respectively 3D printed in wax and casted in sterling silver and 3D printed in a highly detailed plastic, by Shapeways.