Here is my non-competing entry:
CIRCUMFERENCE OF THE DIAMETRIC
Blender 2.79, Cycles, only procedural textures. Some levels / color / saturation adjustments in GIMP.
I wanted to contrast a variety of qualities in this piece:
round vs. angular, simple vs. complex, vividness vs. desaturated, centricity vs. decentralized, openness vs. enclosure, macro vs. micro, softness vs. hardness, wholeness vs. fractional, and more.