CBJ Core Knowledge and Fundamentals 3 — Questions and Answers
Question 1: What is the correct torch tip choice when soldering delicate fine silver wire components?
- Large bushy tip for broad heat coverage
- Small fine tip for pinpoint heat control (Correct answer)
- A rosebud tip for even diffusion
- Any tip is equally appropriate
Correct answer: Small fine tip for pinpoint heat control
A small, fine-tipped torch allows precise heat application to delicate wire without overheating surrounding areas or melting fine details.
Question 2: In the context of precious metal alloys, what does 'fineness' refer to?
- The surface quality of the polished metal
- The parts per thousand of pure metal in an alloy (Correct answer)
- The grain structure visible under magnification
- The melting range of the alloy
Correct answer: The parts per thousand of pure metal in an alloy
Fineness expresses the purity of a precious metal alloy in parts per thousand — for example, 750 fineness equals 18-karat gold (75% pure).
Question 3: Why is pickle solution used after soldering a jewelry piece?
- To harden the solder joint
- To remove flux residue and oxidation (Correct answer)
- To anneal the metal after heat exposure
- To etch decorative patterns into the surface
Correct answer: To remove flux residue and oxidation
Pickle is a mild acid solution that dissolves flux residue and the oxides that form on metal surfaces during soldering.
Question 4: What is the term for the temperature at which a solder alloy begins to melt?
- Liquidus temperature
- Solidus temperature (Correct answer)
- Eutectic point
- Annealing temperature
Correct answer: Solidus temperature
The solidus temperature is the point at which a solder alloy begins to melt; the liquidus is when it is fully liquid — together they define the melting range.
Question 5: A bench jeweler is sizing a ring larger using a ring stretcher. Which metal property makes this possible?
- Malleability (Correct answer)
- Hardness
- Brittleness
- Thermal conductivity
Correct answer: Malleability
Malleability is the property that allows metal to be permanently deformed by compressive forces (like a stretcher) without fracturing.
Question 6: What is the purpose of a burnisher in stone setting?
- To drill pilot holes for prong placement
- To push and compress metal over a stone's girdle (Correct answer)
- To remove metal burrs from the setting
- To polish the stone's table facet
Correct answer: To push and compress metal over a stone's girdle
A burnisher is used to push and work-harden metal bezel walls or prong tips over a stone's girdle to secure it in place.
Question 7: Which of the following best describes a 'hall mark' on jewelry?
- A brand logo stamped by the retailer
- An official mark guaranteeing metal purity, struck by an assay office (Correct answer)
- A decorative motif engraved on the shank
- A weight stamp applied by the refiner
Correct answer: An official mark guaranteeing metal purity, struck by an assay office
A hallmark is an official mark applied by an authorized assay office certifying that the metal meets the stated purity standard.
CBJ Core Knowledge and Fundamentals 3
What is the correct torch tip choice when soldering delicate fine silver wire components?