Diamond cutting

Diamond Cutting Process

• Planning
• Diamond manufacturers analyze diamond rough from an economic perspective
• Objectives: maximum return on investment and quick sale
• Scanning devices used to create a 3D model of the rough stone
• Inclusions photographed and placed on the model for optimal cutting
• Factors influencing cut choice: market trends, original shape of the rough stone, location of inclusions
• Cleaving or Sawing
• Cleaving separates diamond rough into separate pieces
• Groove made with laser or saw, then split with a steel blade
• Cleavage can occur along any of the four planes parallel to the faces of an octahedral diamond
• Sawing uses a diamond saw or laser to cut rough into separate pieces
• Sawing gives diamonds their initial shape
• Bruting
• Polishing

Maximizing Value

• Cut choice influenced by weight retention and popularity of certain shapes
• Weight retention analysis to find optimal combination of finished stones
• Different cuts preferred for different crystal shapes
• Cutting and polishing results in a significant loss of weight (about 50%)
• Compromises may be made to preserve weight or avoid inclusions

Color Retention

• Cutting can influence the color grade of colored diamonds
• Certain cuts intensify the color of the diamond
• Green diamonds often have surface coloration, cut to preserve the color
• Naturals left on the finished gem provide the color to the diamond
• Color enhancement can increase the value of the diamond

Diamond Polishing

• Diamond polishing is the final stage in diamond manufacturing.
• The process involves a diamond crossworker placing the main facets on the diamond to maximize weight, clarity, and angles.
• After the initial crossworking, the diamond is polished by smoothing the main facets.
• The final facets, including the stars and upper and lower girdle facets, are polished by a brillianteer.
• Polishing is done by forcing the diamond against a spinning disk with abrasive.

Final Inspection and Recutting

• Final Inspection
• The final stage of diamond cutting involves thoroughly cleaning the diamond in acids.
• The diamond is then examined to ensure it meets the quality standards of the manufacturer.
• This inspection is crucial to determine the diamond's market value.
• Quality standards include factors such as clarity, color, and cut.
• The inspection ensures that only diamonds meeting these standards are released to the market.
• Recutting
• Diamonds can be recut into new shapes to increase their value and desirability.
• Changes in market preferences and trends often drive the need for recutting.
• For example, the marquise cut diamond lost popularity in later decades and could be recut into an oval or pear shape.
• Recutting can result in a loss of total weight, typically around 5 to 10%.
• Clarity can also be improved through recutting by removing inclusions.

Diamond cutting Data Sources