What is an "Ideal Cut" Diamond?

The ideal cut is a mathematical formula for cutting diamonds to precise angles and proportions to gain the optimum reflection and refraction of light.

The result is a diamond of singular beauty. Also essential to an ideal cut is:

• Polish - the facets should be smooth and absent of any visible marks on the surface.
• Symmetry - the precision of shape and placement of facets.

A finished diamond contains 5 main parts.

• The crown = top area of the diamond above the girdle. The crown has 1 octagonal and 32 triangular/kite flat surfaces called facets which capture light.

• The table = large facet in the center of the crown.

• The girdle = the narrow band circumscribing the edge of the plane which separates the crown and pavilion. It provides a surface to hold diamond in place in a piece of jewelry.

• The pavilion = portion below the girdle sometimes called the base. This is the diamond's most critical part. When cut at the proper angle, light is reflected down to the pavilion from the crown facets and is internally reflective back up to the crown causing brilliance.

• The culet = the pointed end at the bottom of the diamond.

Mathematical Formula for an Ideal Cut Diamond

All diamonds have some brilliance, but an Ideal Cut Diamond offers the optimum play of sparkle, fire, and light.

Factors that Affect a Diamond's Beauty

Three factors than affect the beauty of a diamond are
brilliance, sparkle, and fire.
When a round brilliant diamond is cut to very specific tolerances, an ideal cut, a singular balance of brilliance, sparkle and fire is achieved.

Light Return - Brilliance

Brilliance is the amount or intensity of white light reflected out of the diamond in the face up position. Diamonds that are cut too deep or too shallow leak light through the pavilion detracting from their brilliance.

Sparkle - Scintillation

Sparkle is the flashing effect when a diamond moves. It is the flashing or twinkling of light from the facets. The size of the table affects the sparkle. The larger the table, the less sparkle.

Fire - Dispersion

Fire is the dispersion of white light into various coulors of the rainbow. The fire in an Ideal Cut Diamond produces more flashes of the different spectral colors.