This is my maker coin, i.e. mostly a bespoke showcase object, although I use it as a filament sample now.
The design is inspired by the Eye of Agamotto from Dr. Strange, but it's not a replica.

The coin has four nested parts that rotate on the pivot points. With the included STL file I was able to separate the rings easily with all filaments from regular PLA and PETG to carbon fiber and timberfill (may need to press on the inner ring with something plastic to force it to move for the first time, I used the glue stick case).

The surface finish shown in the photos comes from the slicer (Slic3r): the recessed surface is gyroid infill with no top layer, and the raised surface is the top layer with the Hilbert curve pattern. In order to get different settings in different parts of the model, I used Slic3r modifier mesh, which is the second STL file (3x.stl). It's used to make Slic3r apply different settings to the part of the model inside the "box" created by this second file, so I set the primary settings to print with sparse infill and the Hilbert curve top layer pattern, and the modified settings inside the box are 50% gyroid infill and zero top layers.

Printed on Prusa i3 MK2.5 using a variety of filaments, the ones in the photos are Polyalchemy Elixir Gold, Filamentum Timberfill Rosewood, Atomic translucent green PETG, and Filamentum Vertigo Galaxy.