Cushion Cut Diamonds - A Complete Guide

Cushion Cut Diamond

The cushion cut diamond (once referred to as old mine cut) combines a square cut with rounded corners, much like a pillow - hence the name. This classic cut has been around for almost 200 years, and for the first century of its existence was the most popular diamond shape (similar to round cut today). Until the early 20th century, the cushion cut diamond was the de facto diamond shape.

Traditional cushion cut diamonds return light in a chunkier pattern than modern cuts. Combined with the enlarged culet (which was considered desirable for the pattern created when viewed through the table), this created a distinctive look that is prized today among dealers in antique diamonds.

Partially based on cut research initiated by Marcel Tolkowsky in the 1920's, refinements to cushion cut diamonds over time (such as shrinking the culet, enlarging the table, and improving cut angles for increased brilliance), have led to a resurgence in popularity. Many buyers are attracted to the antique feel combined with modern performance offered by the cushion cut.

Cushion Cut Diamond - Three Pavilion Patterns
Cushion Cut Diamond - Three Pavilion Patterns

The standards for cushion cut vary more than most other shapes, and personal taste will dictate choice. While generally less brilliant than round brilliant diamonds, cushion cut diamonds often have better fire, which is part of their appeal. Modern cushion cuts tend to have one of three basic pavilion facet patterns (see image). The third pattern has an extra row of facets on the pavilion and is classified by GIA as a "modified" cushion cut. These modified cuts tend to have a "crushed ice" or needle like facet pattern, more similar to a radiant cut than a traditional cushion cut.

The chart below serves as a general guideline for evaluating the cut of a cushion cut diamond.

EXCELLENT VERY GOOD GOOD FAIR POOR
Table %
61 - 67 58 - 60
or
68 - 70
56 - 57
or
71
54 - 55
or
72 - 73
< 54
or
> 73
Depth %
61 - 67 58 - 60.9
or
67.1 - 70
56 - 57.9
or
70.1 - 71
54 - 55.9
or
71.1 - 73
< 54
or
> 73
Girdle
Very Thin - Slightly Thick Very Thin
to
Thick
Very Thin
to
Very Thick
Ex. Thin
to
Ex. Thick
Culet
None Very Small Small Medium > Medium
Cushion Cut Diamond LW Ratios
Cushion Cut Diamond LW Ratios.

While the classic cushion cut diamond is a square (with a length to width ratio of 1.00), they are often found in slightly rectangular shapes as well. The most popular shape is a slight rectangle of 1.10-1.20 length to width, however personal preference should dictate choice. Every Lumera Diamond includes precise measurements, as well as the length to width ratio, so you know the exact shape of the cushion cut diamond you are considering.

EXCELLENT VERY GOOD GOOD FAIR POOR
Square 1.00 - 1.03 1.04 - 1.05 1.06 - 1.08 > 1.08
Rectangle 1.15 - 1.20 1.10 - 1.14
or
1.21 - 1.30
1.08 - 1.09
or
1.31 - 1.50
< 1.08
or
> 1.50

Evaluating color in cushion cut diamonds is subjective. Keep in mind that many buyers may actually prefer the ever so slightly warmer colors of a G-H diamond over the cool colorlessness of a D-F diamond. In fact, most of the premium in price associated with cushion cut diamonds at the higher end of the color scale is driven by supply and demand; customers want the D-F color grades, and are willing to pay a premium to get them. In a world without diamond color grading, the price premium for higher grades would be much lower, as the actual differences in color are difficult to perceive.

The color chart below provides a general guide for evaluating color in cushion cut diamonds.

EXCELLENT VERY GOOD GOOD FAIR POOR
< .50 ct. D - G H - I J - K L - M > M
.51-1.0 ct. D - F G H - I J - K > K
1.0-2.0 ct. D - F G - H I - J > J
> 2.0 ct. D - F G H - I > I
Fluoro
None Faint - Med. Strong Very Strong

Like color, evaluating clarity in cushion cut diamonds is subjective. GIA provides excellent help with their clarity grades. Still, it is important to understand that each customer will have a unique standard for clarity. Some may be perfectly comfortable with an inclusion as long as they cannot easily see it. Others may insist on a more technically flawless appearance. The clarity chart below provides a general guide for evaluating clarity in cushion cut diamonds.

EXCELLENT VERY GOOD GOOD FAIR POOR
< .50 ct. FL - VS2 SI1 - SI2 I1 I2 > I2
.51-1.0 ct. FL - VS1 VS2 - SI1 SI2 I1 - I2 > I2
1.0-2.0 ct. FL - VVS2 VS1 - VS2 SI1 - SI2 I1 > I1
> 2.0 ct. FL - VVS2 VS1 - VS2 SI1 SI2 > SI2

Questions about shape or other aspects of a diamond? Ask a diamond consultant for answers. A consultant will answer any questions you have, and if you like, search for diamonds on your behalf that match your criteria. chat online, or send your request to consultant@lumeradiamonds.com.

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