| |
| |
 |
| |
| Marking |
| |
 The first step in the diamond making process, marking is done after examining each rough diamond to decide how it should be cut to yield the greatest value. The shape of the rough diamond and the number and location of inclusions, or blemishes, are first considered. Since the crystalline structure of diamond causes it to have a grain (called cleavage), it is critical to plan for the facets of the diamond to be made in the correct direction. Taking these factors into account, the planner decides how the diamond should be cut and marks it to indicate where the stone should be cleaved or sawed.
Cleaving 
After a diamond is marked it is sent to a cleaver or a sawyer, depending on the stone. When the stone is very large and valuable, cleaving it is a critical process, because a mistake by the planner or the cleaver can shatter the diamond. The cleaver's job is to cut the diamond into two pieces to bring out the best angles and establish what the final cut will be. Cleaving is performed by striking the stone with a sharp blow from a blade or hammer. However, some stones have too many stress points and might fragment if cleaved, so they must go to the sawyer. This process is extremely meticulous and time-consuming. 
Sawing
The saw used in diamond processing is a paper-thin disk of phosphor bronze that rotates on a horizontal spindle at about 4,000 rpm. The diamond is clamped so it rests against the blade and is sawed for several hours, depending on the size of the diamond. Since diamond is the hardest substance on earth, it can only be cut by another diamond. Therefore, diamond dust is used on the saw, as well as the actual diamond dust generated by the crystal being cut. |
| |
|
|  Cutting
The next step in cutting a round stone is called girdling, or rounding. The diamond is placed in a lathe and a second diamond is held against it using a long handle, which slowly rounds it into a cone shape. The next step is for the stone to go to the blocker, who specializes in placing the first 18 main facets on a brilliant-cut diamond. It  then goes to the brillianteer, who places and polishes the remaining 40 facets (if the stone is being cut in the standard 58-facet brilliant cut).
Polishing
The last step in the diamond finishing process is polishing. The diamond is clamped onto a revolving cast-iron lap (a horizontal, circular disk) that has been charged with diamond dust. The fine diamond dust acts as an abrasive to polish away small imperfections and make the surface of the stone perfectly smooth. |
|
|
|
| |
|
|
|
