A saw blade enters the octahedral diamond crystal at the center point to create two equal halves.

A saw blade enters the octahedral diamond crystal off center to create two different sizes.

 

A rough crystal is most often sawed into two pieces. The layout begins by marking the rough crystal with a special ink along the plane in which it will be sawn. In order for a cutter to get a maximum investment return, he must also consider the final weight categories. For example, it would be more profitable for the cutter to finish with a 1.02 ct. and 1.51 ct. versus another possible scenario of a 1.08 ct. and a 1.45 ct. The difference could mean taking a profit or a loss. By shifting either the saw plane or the layout of the stone ever so slightly, the outcome inevitably changes. This is why odd sizes just under the beginning of new weight categories are much less common. Examples: 0.99, 1.46, 1.95, 2.96, etc. Since these sizes are so close to the next weight category, the price per carat is generally significantly higher than its even-sized counterparts, but still not quite the value of the higher weight category. Example: 1.47 versus 1.05 carat. They’re in the same weight category but the price per carat will be higher for the 1.47 (close to a 1.50) due to its greater rarity.