CBJ Quality Assurance and Improvement 3 — Questions and Answers
Question 1: In quality control, what does 'tolerance' refer to in the context of stone setting?
- The maximum amount of inclusions acceptable in a gemstone
- The allowable range of variation in a measurement or fit (Correct answer)
- The chemical resistance of the metal to cleaning agents
- The number of prongs required per carat weight
Correct answer: The allowable range of variation in a measurement or fit
Tolerance defines the acceptable range of deviation from a target measurement, such as the allowable looseness in a bezel fit.
Question 2: What does a 'figure-8' motion during hand polishing accomplish that a straight stroke does not?
- It removes metal faster from high spots
- It prevents directional scratching and produces a more even finish (Correct answer)
- It heats the metal more evenly for better compound adhesion
- It allows the jeweler to detect porosity by feel
Correct answer: It prevents directional scratching and produces a more even finish
A figure-8 polishing motion continuously changes the direction of abrasion, preventing parallel scratch lines and creating a uniform surface.
Question 3: Why should a finished piece be inspected under both direct and raking light?
- Direct light checks color; raking light checks karat content
- Raking light highlights surface scratches and texture flaws invisible under direct light (Correct answer)
- Direct light is used for gemstones; raking light is used for metal only
- Both are required to satisfy GIA grading standards
Correct answer: Raking light highlights surface scratches and texture flaws invisible under direct light
Raking (oblique) light casts shadows across surface irregularities, making scratches, dents, and tool marks visible that direct illumination would flatten out.
Question 4: Which of the following best describes the quality standard for a channel-set row of stones?
- Stones may vary slightly in height as long as they are secure
- All stones should sit at a uniform height with consistent spacing (Correct answer)
- Every other stone may be slightly recessed for visual effect
- Stones should be flush with the channel rail on one side only
Correct answer: All stones should sit at a uniform height with consistent spacing
A properly finished channel setting requires all stones to sit at equal height and with even spacing for both structural integrity and aesthetic quality.
Question 5: What is the correct procedure if a prong tip cracks during the burnishing process?
- Continue burnishing and polish over the crack
- Apply flux and re-solder the tip, then re-burnish gently (Correct answer)
- Replace the stone and rebuild the entire setting
- File the crack smooth and apply rhodium plating
Correct answer: Apply flux and re-solder the tip, then re-burnish gently
A cracked prong tip must be repaired by removing the stone if needed, re-soldering or adding metal, and then carefully re-burnishing to avoid recurrence.
Question 6: When evaluating a pavé-set piece, which quality indicator is checked first?
- The brightness and cut grade of each stone
- That every stone is secure with no rocking or spinning (Correct answer)
- The uniformity of the bead size across the surface
- Whether the metal has been rhodium plated uniformly
Correct answer: That every stone is secure with no rocking or spinning
Security of each stone is the primary quality check in pavé work; even one loose stone indicates a setting deficiency that must be corrected.
Question 7: Which finishing step should always be performed before rhodium plating a white gold piece?
- Laser welding any surface pits
- Thorough polishing and ultrasonic cleaning to remove all surface contaminants (Correct answer)
- Applying a firescale inhibitor coating
- Annealing the metal to relieve internal stress
Correct answer: Thorough polishing and ultrasonic cleaning to remove all surface contaminants
Rhodium plating requires a perfectly clean, polished surface; any contamination or scratches will show through the thin plating layer.
CBJ Quality Assurance and Improvement 3
In quality control, what does 'tolerance' refer to in the context of stone setting?