Education for Cut - DiamondHouseAZ.com
The cut/proportions of a diamond is seen by the diamond industry as the most important characteristic of a diamond.
Cut refers to the angles and proportions a skilled craftsman creates in transforming a rough diamond into a polished diamond. A well-cut diamond will reflect light internally from one mirror-like facet to another, dispersing it through the top of the stone. Cuts that are too deep or too shallow lose or leak light through the side or bottom, affecting the diamond's brilliance.
Diamond cutting requires great skill and training. The cutter must polish tiny surfaces known as facets onto the rough diamond. This process is what creates the facets known as the crown, culet, table, girdle and pavilion of the diamond. The facets, when arranged in precise proportions, will maximize the fire life and brilliance of a diamond. To cut a diamond perfectly, a craftsman will often need to cut away more than 50% of the rough diamond.
From one side of the girdle to the other side of the girdle is 100% of a diamond's diameter. The top portion of a diamond, the table, covers a percentage of that 100%. The table does not cover the entire 100% because the crown angle takes up some of the percentage. The optimal table % is between 53% and 64%.
Cutting style is categorized into three basic types: step-cut, brilliant-cut and mixed-cut. The difference among these three types is the facets of each style. Brilliant-cuts are scientifically found to reflect the most light. Step-cuts have rows of facets that resemble the steps of a staircase. The emerald and baguette are examples of this cutting style. Mixed-cuts have both step and brilliant-cut facets. One of the most popular types of mixed-cuts is the Princess Cut.
The cut of a diamond can also refer to its shape and what shape you choose depends on your preference. In the diamond industry, diamonds are typically broken down into two different shape categories: the Round Brilliant and Fancy Shapes. Please refer below to a brief description of some of the most popular shapes.
Round Brilliant Diamonds
The Round Brilliant cut is still the most sought after diamond. The modern
Round Brilliant consists of 58 facets (or 57 if the culet is excluded); 33 on the crown (the top half above the middle or girdle of the stone) and 25 on the pavillion (the lower half below the girdle). In recent decades, most girdles are faceted. Many girdles have 32, 64, 80, or 96 facets; these facets are not counted in the total. The depth percentage of a round brilliant diamond should range between 58 to 64 percent and the table percentage should range between 53 to 64 percent. The most desired percentages are the 60 percent, and perfectionists will look for depth of 59 through 62 percent and table of 56 through 58 percent.
Round Brilliant consists of 58 facets (or 57 if the culet is excluded); 33 on the crown (the top half above the middle or girdle of the stone) and 25 on the pavillion (the lower half below the girdle). In recent decades, most girdles are faceted. Many girdles have 32, 64, 80, or 96 facets; these facets are not counted in the total. The depth percentage of a round brilliant diamond should range between 58 to 64 percent and the table percentage should range between 53 to 64 percent. The most desired percentages are the 60 percent, and perfectionists will look for depth of 59 through 62 percent and table of 56 through 58 percent.
Marquise Cut Diamonds
For the Marquise cut diamond, a length-to-width ratio (the length of a
diamond divided by the width of a diamond) between 1.75:1 to 2:1 is most
desired. However, as with any other fancy shape, the consumer's individual
taste constitutes an element of the evaluation as well. The typical
marquise diamond contains 56 facets.
diamond divided by the width of a diamond) between 1.75:1 to 2:1 is most
desired. However, as with any other fancy shape, the consumer's individual
taste constitutes an element of the evaluation as well. The typical
marquise diamond contains 56 facets.
Princess Cut Diamonds
The Princess cut diamond is a brilliant style shape with sharp, uncut
corners. It is typically cut square rather as a rectangle. Brilliant style refers
to vertical direction crown and pavilion facets instead of step style
horizontally facets. A princess Cut Diamond generally has 76 facets, giving
it more brilliance and fire than the round brilliant. The Princess Cut diamond
is the most popular fancy shape in the
United States
.
corners. It is typically cut square rather as a rectangle. Brilliant style refers
to vertical direction crown and pavilion facets instead of step style
horizontally facets. A princess Cut Diamond generally has 76 facets, giving
it more brilliance and fire than the round brilliant. The Princess Cut diamond
is the most popular fancy shape in the
Radiant Cut Diamonds
The Radiant cut diamond is a straight-edged rectangular or square stone
with cut corners. The radiant cut diamond has 62-70 facets.
with cut corners. The radiant cut diamond has 62-70 facets.
Emerald Cut Diamonds
An Emerald cut diamond shape is usually rectangular. The length-to-width
ratio of an Emerald Cut Diamond should be between 1.5:1 to 1.75:1.
ratio of an Emerald Cut Diamond should be between 1.5:1 to 1.75:1.
Pear Shaped Diamonds
The Pear shaped brilliant diamond is based upon the traditional
configuration of the round brilliant diamond. More than other fancy shapes,
length-to-width ratio is a matter of taste when it comes to pear shaped
diamonds. Because pears may be used for engagement rings, an accent in
a necklace, dangles in earrings, and integral parts of custom designs, a
wide variety of shapes is considered desirable. The typical pear shaped
diamond will contain 58 facets.
configuration of the round brilliant diamond. More than other fancy shapes,
length-to-width ratio is a matter of taste when it comes to pear shaped
diamonds. Because pears may be used for engagement rings, an accent in
a necklace, dangles in earrings, and integral parts of custom designs, a
wide variety of shapes is considered desirable. The typical pear shaped
diamond will contain 58 facets.
Oval Cut Diamonds
The Oval cut diamond is based upon the traditional configuration of the
round brilliant cut diamond and that's why its technical name is oval
modified brilliant diamond. A length-to-width ratio of 1.5:1 is almost
universally considered a pleasing shape for oval diamonds, with any
variation beyond 1.4:1 or 1.6:1 beginning to be noticeable and become an
aesthetic issue. However, as with all fancies, a certain degree of individual
taste is always factored into the desirability of a particular diamond's
shape. 56 facets are typical for oval brilliant diamonds.
round brilliant cut diamond and that's why its technical name is oval
modified brilliant diamond. A length-to-width ratio of 1.5:1 is almost
universally considered a pleasing shape for oval diamonds, with any
variation beyond 1.4:1 or 1.6:1 beginning to be noticeable and become an
aesthetic issue. However, as with all fancies, a certain degree of individual
taste is always factored into the desirability of a particular diamond's
shape. 56 facets are typical for oval brilliant diamonds.
Heart Shaped Diamonds
The Heart shape diamond is a Valentine's favorite. The width will usually
be 10% wider than the head-to-point length.
be 10% wider than the head-to-point length.
Asscher cut Diamonds
The Asscher cut is a modified square cut Emerald characterized by a
smaller table and larger step facet than the Emerald cut. It features
dramatic, cut corners. It usually has a high crown and a deeper pavilion.
Because of its high crown and small table, the Asscher cut has more light
and fire than the Emerald cut.
smaller table and larger step facet than the Emerald cut. It features
dramatic, cut corners. It usually has a high crown and a deeper pavilion.
Because of its high crown and small table, the Asscher cut has more light
and fire than the Emerald cut.
Cushion Cut Diamonds
The Cushion cut was evolved from the 'Old Mine Cut' that was developed
before the turn of the century. A cushion cut is square to rectangular cut
with rounded corners and 58 brilliant facets that resemble a pillow shape.
before the turn of the century. A cushion cut is square to rectangular cut
with rounded corners and 58 brilliant facets that resemble a pillow shape.
A diamond’s shape can affect its cost. For example, The Round Brilliant Cut is more expensive than any Fancy Shape.
However, all Fancy Shapes should be of equal value given that the overall proportions and grading are of equal standards. Please see the example below:
| Shape: |
Radiant |
Cushion |
| Carat Weight: |
1.00 |
1.00 |
| Color: |
D |
D |
| Clarity: |
VS1 |
VS1 |
| Measurements: |
6.61 - 5.28 x 3.55 |
6.57 - 5.28 x 3.55 |
| Table: |
65% |
65% |
| Depth: |
67.2% |
67.2% |
| Flourescence: |
None |
None |
| Girdle: |
Medium Faceted |
Medium Faceted |
| Culet: |
None |
None |
| Certificate |
GIA |
GIA |
| Cost: |
$4500 |
$4500 |
However, this is not always the case. The number of diamonds, or lack thereof, of a given shape in the diamond market can increase or decrease its value. For example, some Fancy Shapes like Horseheads, Half Moons, Trapezoids, Shields, Kites, Bullets., etc. are more rare, and therefore, will be more expensive.
