What Makes a Diamond Have Appealing Contrast?

A diamond with positive contrast has a distribution of bright and dark facets that change as the stone is rocked from side to side. The diamond's dark faces highlight its neighboring light faces and contribute to the stone's overall brilliance. Very large diamonds may actually have less attractive contrast than medium sized diamonds because large diamonds' facets are large and separated one from another. Tiny diamonds, on the other hand, may have great contrast but it will be difficult to appreciate it because the faces are so small. Three additional factors contribute to a diamond's contrast, its depth, head interference, and symmetry. Diamonds that have a deep pavilion leak light from the bottom and so most of the facets will appear dark. Diamonds that are shallow leak light from the sides, so the stone will have less contrast. Diamonds with the perfect (Tolkalsky) cut also have dark facets, but they are fewer in number, triangular, and contributory to the diamond's appealing contrasts. Head interference also influences diamonds' contrast. If the stones are cut so that light going in comes right back out to the viewer, than the viewer's head, which blocks the light source, will make the diamonds appear dark. In well cut diamonds, light coming in from the sides will be reflected back into the eyes of the viewer giving the diamonds a shiny appearance. Symmetry also plays an important role in creating beautiful diamond contrast. A well proportioned diamond creates the most beautiful contrasts.