This is the world's most favored cut, and as the name suggests the shape in the diamond is round allowing a lot of light to flood with the facets and make a brilliant sparkle. This shape is most commonly useful for solitaires which allow light from the bottom cone, or pavilion because it's known, further enhancing the sparkle. This cut suits almost any hand and personality and is also an ideal diamond engagement ring.
The best fitness tip for building up your arms is to work opposite muscles in opposite sets of each other. The best example would be to work the triceps and then the biceps. Each has the opportunity to rest while the other is being worked. This minimizes your time and maximizes your workout.