Gold Design Gold Purity and Alloys 1 — Questions and Answers
Question 1: What does the hallmark '750' stamped on gold jewelry indicate?
- 750 grams of gold
- 75% pure gold, equivalent to 18 karats (Correct answer)
- 750 parts per thousand silver
- 7.5 karat gold
Correct answer: 75% pure gold, equivalent to 18 karats
The hallmark 750 indicates 750 parts per 1,000 are pure gold, which is 75% gold purity — the European marking for 18 karat gold.
Question 2: Which alloy is typically added to yellow gold to create 14k gold?
- Pure platinum
- A mixture of copper, silver, and zinc (Correct answer)
- Pure silver only
- Palladium
Correct answer: A mixture of copper, silver, and zinc
14k yellow gold alloy typically contains gold mixed with copper, silver, and sometimes zinc to achieve 58.3% gold content.
Question 3: What gives rose gold its distinctive pinkish-red color?
- Added zinc
- Higher iron content
- A higher proportion of copper in the alloy (Correct answer)
- Added chromium
Correct answer: A higher proportion of copper in the alloy
Rose gold's characteristic warm pink color comes from a higher concentration of copper in the gold alloy — typically around 25% copper in 18k rose gold.
Question 4: Which karat gold is considered 'pure' gold and contains no other metals?
- 22 karat
- 18 karat
- 24 karat (Correct answer)
- 14 karat
Correct answer: 24 karat
24 karat gold is 99.9% pure gold with no significant alloying metals — the highest purity commercially available.
Question 5: Why is 24k gold rarely used for everyday jewelry in the US despite being the purest?
- It is too heavy
- It is too soft and malleable, making it prone to scratching and bending easily (Correct answer)
- It cannot be set with gemstones
- It is illegal to sell pure gold jewelry in the US
Correct answer: It is too soft and malleable, making it prone to scratching and bending easily
24k gold's softness (Mohs 2.5) means it bends, scratches, and deforms easily in everyday wear — alloyed golds are far more durable.
Question 6: What is the gold content of 10 karat gold, the minimum legal karat for jewelry sold as 'gold' in the US?
- 41.7% (Correct answer)
- 58.3%
- 75%
- 91.7%
Correct answer: 41.7%
10 karat gold is 10/24 = 41.7% pure gold, and it is the minimum gold content legally permitted to be sold as 'gold' jewelry in the United States.
Gold Design Gold Purity and Alloys 1
What does the hallmark '750' stamped on gold jewelry indicate?