depth %

The distance between the culet and the table of a gemstone. The depth percent represents the diamond's height as a proportion of the girdle diameter.

polish

The finish of the diamond's facets is described by this term. The grades for polish include Ideal, Excellent, Very Good, Good, Fair, and Poor. Polish grades of Good or higher have the least impact on the diamond's brilliance and are appropriate for high-end jewelry. Polish is included in an overall cut grade by some gem labs, such as Gemscan.

l/w ratio

The length-to-width ratio compares a diamond's length to its width to determine how elongated a fancy-shaped diamond appears when viewed from above. Personal choice dictates the length-to-width ratio, with some preferring a more elongated shape and others preferring a more equal or square shape.
Ex. A princess-cut diamond that measures 5.05 mm long by 5.00mm has a length-to-width ratio of 1.01 (5.05/5.00) and will appear perfectly square.
Most popular length-to-width ratios:

• Princess: 1.00-1.05
• Radiant: 1.00-1.05
• Asscher: 1.00-1.05
• Cushion: 1.00-1.05
• Heart: 0.90-1.10
• Emerald: 1.30-1.40
• Oval: 1.30-1.70
• Pear: 1.45-1.75
• Marquise: 1.75-2.30

Fluorescence

The response of a diamond to ultraviolet light is described in this definition. There may be some obstruction with the flow of light in diamonds with strong or very strong fluorescence, giving them a milky or slick look.

table %

At the peak of a gemstone, the largest facet is found. The table width defined as the proportion of the girdle diameter is termed as table percent.

symmetry

The alignment of the diamond's facets is described by this term. The diamond's facets may be misaligned, resulting in poor light reflection. Ideal / Excellent, Very Good, Good, Fair, or Poor symmetry is rated. Symmetry grades of Good or better have the least impact on the diamond's brilliance and are appropriate for high-end jewelry. Symmetry is factored into the total Cut grade by some gem labs, such as Gemscan.