DDG ASS #8 Key Terms & Concepts PDF

DDG ASS #8: Key Terms Bearding—The appearance of minute or minor fractures perpendicular to a bruted girdle. Blocking—Placing the first 17 or 18 facets on a diamond, including the crown and pavilion main facets, table, and sometimes a culet. Brillianteering—Placement and polishing of th...

DDG ASS #8: Key Terms Bearding—The appearance of minute or minor fractures perpendicular to a bruted girdle. Blocking—Placing the first 17 or 18 facets on a diamond, including the crown and pavilion main facets, table, and sometimes a culet. Brillianteering—Placement and polishing of the star and upper and lower half facets. Bruting—The process by which a rough diamond is shaped into its basic face-up outline to prepare it for faceting. Cleaving—The process of dividing rough diamond along its cleavage planes. Coning—The process of forming the pavilion angle by gradually polishing off the extra material at different angles. Dop—A holder that secures a diamond during processing. Kerf—A notch scratched into diamond rough to prepare it for cleaving. Old European Cut—An early brilliant cut with a circular girdle. Old Mine Cut—An early cushion-shaped brilliant cut with a high crown, deep pavilion, 58 facets, and a large culet. Planner—A person who studies the diamond rough, develops cutting plans, and marks the plans on the rough. Polishing—Placing and finishing facets on a rough diamond. Rose Cut—A diamond cut with a flat bottom and triangular facets that come to a point at the top. Sawing—The process of dividing a rough diamond into different sections using a saw. Single Cut—A simple diamond cut, with a table, eight crown facets, eight pavilion facets, and sometimes a culet. Tang—A device that holds a dop and allows a cutter to adjust and maintain a diamond’s angle during polishing. Key Concepts Before the 15th century, diamond “cutting” was limited to superficial polishing of the rough. The 16th-century developments of continuous rotary motion and the cast-iron polishing wheel shifted diamond cutting from superficial polishing to genuine faceting. The inventions of the bruting machine and the motorized diamond saw made mass production of faceted diamonds possible. Rough mapping, computerized planning, and laser processing made diamond cutting more efficient and more profitable. The point cut and table cut followed the shape of the octahedral diamond rough. The rose cut provided an efficient way to use flattened or cleaved diamond rough. The single cut was the basis for the full-cut modern brilliant. The cushion shape was easier to cut before the bruting machine’s invention due to its resemblance to the natural outline of octahedral diamond crystals. The round brilliant is the dominant diamond cut in today’s market. Cutters apply the brilliant cut to fancy shapes to maximize profit from oddly shaped or off-color rough. Technological breakthroughs made fancy brilliants easier to make and more affordable. Diamond cut trends change over time and with location. Modern planning technology benefits from the combination of diamond rough mapping and computer-aided planning. Laser sawing can split a rough diamond in any direction. Laser sawing is more precise and efficient than blade sawing and has greater weight retention. Water-jet-guided laser sawing provides greater working range, better focus, higher weight retention, and lower risk for strained rough. Laser bruting is especially helpful for fancy-shape diamond manufacturing. Coning is commonly done on round-shape diamonds and reduces potential damage to strained stones. Quality control is crucial for modern diamond cutting businesses due to the high standards of the market.