Square the Circle by Hubert Verstraeten
Hubert Verstraeten has managed to Square the Circle – with rings which are round when worn on one side, and square when worn on the other side. Without any perceptible transition, the inside of the ring changes from a circle to a square. A geometric puzzle game in gold and platinum, with or without diamonds, visible only at the second look on the smooth, round or square, outer shape of the ring. I urge you to check out the various styles. This has to be one of the coolest rings I’ve ever seen.