Inverted bone style gyroid - yet a smaller version.
This isosurface (a math thing) has a triple symmetry axis, point symmetry and 12 of 180° symmetry axes. The surface is created by a fairly simple rule made from trigonal functions (sin/cos). The inversion does not even impact the symmetry. And the covergence on top of all - the gyroid reflects the symmetry properties of Quartz crystals - wich make up 60% of mother earth's rocky matter ... :-)
As I think the "uninverted" version does not really rock, I'm just publishing the inverted one. Please uninvert your self! To do so you simply put the object at the origin of your world and simply calculate 1/x where x is the every position in your world.