Size is as-packaged, or the diameter of loose marbles. ("D" is the diameter of round items other than marbles.)
This marble's design is very busy. The core contains a hurricane of pastels swirled on a black base - soft greens, blues and yellows. This core is cased in a layer of crystal clear. Floating above the core, on the outside of the casing are multiple five-petal blooms. A real beautiful design.