Emerald Cut Approximate carat weight of an Emerald Cut diamond=Length x Width x Depth x 0.0089 The above weight formula provides an estimate. The actual weight may vary up to 10%, depending on the make, girdle thickness, and accuracy of the measurement tools.   Grading an Emerald Cut diamond for clarity is more difficult than it seems. Although it is often easier to see the inclusions within the Emerald Cut diamond, it is more difficult to determine what grade to give these inclusions. This due to the straight cut or step cut of the Emerald Cut. A VS1-VS2 might appear visible to the unaided eye in an Emerald Cut. We therefore recommend that the clarity grade be upgraded by one or two grades in order for the grading to be comparable to a Radiant Cut or Princess Cut, or any Brilliant Cut for that matter. A nice shape for an Emerald Cut is a 1.5 x 1 ratio. A 1.7 x 1 ratio is considered to be long, A 1.3 x 1 ratio is considered to be squarish. (See Table and Depth Percentage Formulas .) . Table of Contents Encyclopedia Home Introduction The 4 C's Terminology Depth and Table Percentages How to use The Diamond Buying Guide GIA, AGS, & Commercial Grade Conversion Charts Round Brilliant , Brilliant, Old Mine Cut Pear and Oval Cuts Marquise Cut Heart Shape Princess and Radiant Cuts Emerald, Cushion, and Carre Cut Trillions   Cushion Cut is an old mine cut Emerald Cut with rounded off girdles and an asymmetrical or 'off' shape. To recut a Cushion Cut to an Emerald Cut, the diamond will lose 20-25% of its original weight. In order to estimate the value of a Cushion Cut diamond, grade the color and clarity of the diamond, deduct 20-25% from the original weight, and look up the price per carat on the corresponding chart for the lower weight. Carre Cut An older version of the modern Emerald Cut, the Carre Cut is square with a pointed culet. It is also called a Step Cut. The Carre Cut is usually recut to a Princess or Radiant cut with only 10% weight loss.