Exam Questions And Correct Answers

Ohio Jeweler Certification Practice Exam Questions And Correct Answers (Verified Answers) Plus Rationales 2025|2026 Q&A | Instant Download Pdf

• Which metal is most commonly used as the standard for measuring the

purity of gold?

• Palladium
• Silver
• Gold itself
• Platinum

Rationale: Karat purity compares gold content to pure gold, so gold is the

reference metal.

• 18K gold contains what percentage of pure gold?

A. 50%

B. 58.3%

C. 75% 1 / 3

D. 90%

Rationale: Gold purity is parts of 24; 18/24 = 75% pure gold.

• Which gemstone ranks highest on the Mohs hardness scale?
• Topaz
• Sapphire
• Emerald
• Diamond

Rationale: Diamond is the hardest natural mineral, rated 10 on the Mohs

scale.

• A loupe typically used in jewelry inspection has what magnification?
• 5x
• 8x
• 10x
• 20x

Rationale: Standard gemological grading requires a 10x magnification

lens.

5. The term "annealing" refers to:

• Rapidly cooling metal
• Softening metal through heat
• Adding alloy to metal
• Removing oxidation

Rationale: Annealing heats metal and allows it to cool slowly to increase

flexibility. 2 / 3

• Which type of setting uses small beads of metal to hold the stone in

place?

• Channel
• Prong
• Pave
• Bezel

Rationale: Pave settings secure stones with tiny metal beads for a surface-

set look.

• Sterling silver is what purity?

A. .800

B. .875

C. .925

D. .999

Rationale: Sterling silver is 92.5% pure silver mixed with copper or another

alloy.

• Which gemstone is commonly heat-treated to improve color?
• Diamond
• Peridot
• Sapphire
• Garnet

Rationale: Sapphires are frequently heat treated to deepen or homogenize

color.

• / 3