This was made using a combination of Inventor for the original shape and then it was Voronoi-ed in MeshLab. The final shape I guess you could say is a Voronoi Triangular Toroid?

Anyways, to add to the uniqueness of the pendant, I paused the print mid-way through and dropped a couple ball bearings into the interior cavity. They're free to roll around the inside of the pendant and it adds a nice little extra something to the design.

Print this vertically as shown in the picture. Utilize supports only on the bottom surface if possible to aid in adhering to the bed while printing.