CBJ Core Knowledge and Fundamentals 2 — Questions and Answers
Question 1: What is the primary purpose of annealing a metal during bench jewelry work?
- To harden the metal for stone setting
- To restore ductility after work-hardening (Correct answer)
- To increase the metal's melting point
- To improve surface reflectivity
Correct answer: To restore ductility after work-hardening
Annealing relieves internal stress and restores ductility to work-hardened metal by heating it to a specific temperature and allowing controlled cooling.
Question 2: Which of the following alloys is classified as a sterling silver?
- 92.5% silver and 7.5% copper (Correct answer)
- 90% silver and 10% gold
- 95% silver and 5% zinc
- 88% silver and 12% nickel
Correct answer: 92.5% silver and 7.5% copper
Sterling silver is a legally defined alloy consisting of 92.5% pure silver and 7.5% other metals, typically copper.
Question 3: When using a flexible shaft machine, which handpiece is best suited for wax carving?
- High-speed handpiece at 50,000 RPM
- Low-speed handpiece with a round bur (Correct answer)
- A pneumatic handpiece
- A barrel-style chuck handpiece
Correct answer: Low-speed handpiece with a round bur
A low-speed handpiece with appropriate burs prevents wax from melting due to friction heat and offers better control during carving.
Question 4: What does the term 'work hardening' describe in metalsmithing?
- A heat treatment that permanently strengthens metal
- Metal becoming stiffer and more brittle from mechanical deformation (Correct answer)
- Adding alloy elements to increase hardness
- Quenching hot metal in water to lock hardness
Correct answer: Metal becoming stiffer and more brittle from mechanical deformation
Work hardening occurs when repeated mechanical stress (bending, hammering) dislocates the metal's crystal structure, making it harder and more brittle.
Question 5: A jeweler needs to solder a jump ring closed on a finished gold necklace. Which solder should be chosen to avoid visible seams?
- Easy solder with a lower gold content
- Hard solder with the same karat as the piece (Correct answer)
- Silver solder for strength
- Medium solder regardless of karat
Correct answer: Hard solder with the same karat as the piece
Using solder that matches the karat of the piece ensures the seam blends in color and value, making it nearly invisible after finishing.
Question 6: What is the Mohs scale used to measure in gemology?
- Specific gravity of a gemstone
- Refractive index of a stone
- Relative scratch resistance of minerals (Correct answer)
- Brilliance of a faceted gemstone
Correct answer: Relative scratch resistance of minerals
The Mohs hardness scale ranks minerals from 1 (talc) to 10 (diamond) based on their resistance to being scratched by another material.
Question 7: Which type of file cut leaves the roughest surface on metal?
- Smooth cut
- Second cut
- Bastard cut (Correct answer)
- Dead smooth cut
Correct answer: Bastard cut
Bastard cut files have the coarsest teeth of the standard file grades and remove material quickly but leave a rough surface finish.
CBJ Core Knowledge and Fundamentals 2
What is the primary purpose of annealing a metal during bench jewelry work?