CBJ Metal Properties and Alloys 1 — Questions and Answers
Question 1: What karat value represents pure gold?
- 10K
- 14K
- 18K
- 24K (Correct answer)
Correct answer: 24K
Pure gold is 24 karat, representing 100% gold content with no alloying metals.
Question 2: Which precious metal used in jewelry has the highest melting point?
- Gold
- Silver
- Platinum (Correct answer)
- Palladium
Correct answer: Platinum
Platinum melts at approximately 1,768°C, the highest melting point among common jewelry metals.
Question 3: What percentage of silver does sterling silver contain?
- 75%
- 92.5% (Correct answer)
- 95%
- 99.9%
Correct answer: 92.5%
Sterling silver is 92.5% pure silver alloyed with 7.5% other metals, typically copper, indicated by the .925 hallmark.
Question 4: What property describes a metal's ability to be drawn into wire without breaking?
- Malleability
- Ductility (Correct answer)
- Hardness
- Brittleness
Correct answer: Ductility
Ductility is the property that allows metal to be stretched or drawn into wire without fracturing.
Question 5: Which alloying metal primarily gives yellow gold its hardness and warm color?
- Silver
- Copper (Correct answer)
- Zinc
- Nickel
Correct answer: Copper
Copper is the primary hardening alloy in yellow gold and contributes to its warm yellow-orange tone.
Question 6: Which gold alloy exhibits a greenish hue due to a high silver content?
- Rose gold
- White gold
- Green gold (electrum) (Correct answer)
- Yellow gold
Correct answer: Green gold (electrum)
Green gold, historically called electrum, is alloyed with a high percentage of silver, which imparts a greenish tint.
CBJ Metal Properties and Alloys 1
What karat value represents pure gold?