The connection between the cut and the fire of a diamond
The CUT of a diamond is highly relevant to its FIRE: the colored sparkle a diamond displays when exposed to light. The high dispersion of a diamond is the reason it is able to sparkle in all colors of the rainbow – providing that it has a beneficial cut.
Diamonds are colorless by nature, but the right cut can transform them: a varying refraction of incoming rays of light creates a VARIETY OF COLORS. If the cut is not ideal, e.g. too pointed or too flat, this popular effect is not achieved. Only a cut with ideal proportions lets the light wander from facet to facet and reflect it back into the eye of the beholder.