GIA Diamond Grading & Classification 3 — Questions and Answers
Question 1: What is the weight in carats of a diamond that weighs 0.20 grams?
- 1.00 ct (Correct answer)
- 0.20 ct
- 2.00 ct
- 0.02 ct
Correct answer: 1.00 ct
One metric carat equals 0.20 grams, so a 0.20 g diamond weighs exactly 1.00 carat.
Question 2: On the GIA clarity scale, which grade immediately above SI2 indicates inclusions that are 'noticeable' to a skilled grader under 10x?
- SI1 (Correct answer)
- VS2
- I1
- VVS1
Correct answer: SI1
SI1 (Slightly Included 1) sits directly above SI2; inclusions are noticeable under 10x magnification but typically eye-clean.
Question 3: Which phenomenon describes white light separating into spectral colors as it passes through a diamond's facets?
- Fire (Correct answer)
- Brilliance
- Scintillation
- Fluorescence
Correct answer: Fire
Fire refers to the dispersion of white light into rainbow-colored flashes, a key component of a diamond's visual appeal.
Question 4: A grader notes a feather in a diamond's girdle. What is a feather?
- A small fracture or crack within the diamond (Correct answer)
- A group of pinpoint inclusions forming a hazy area
- A mineral crystal trapped inside the diamond
- A surface chip along the girdle edge
Correct answer: A small fracture or crack within the diamond
A feather is a fracture in a diamond; when viewed at certain angles it can resemble a feather.
Question 5: In GIA color grading, the 'near colorless' range includes which letter grades?
- G, H, I, J (Correct answer)
- D, E, F
- K, L, M
- N through R
Correct answer: G, H, I, J
GIA classifies G through J as 'Near Colorless,' a range where color is difficult to detect without comparison stones.
Question 6: Which of the following best describes an 'ideal' girdle thickness for a round brilliant diamond?
- Thin to slightly thick (Correct answer)
- Extremely thin
- Extremely thick
- Very thick
Correct answer: Thin to slightly thick
GIA considers a girdle ranging from thin to slightly thick as optimal, balancing durability with proportion efficiency.
Question 7: What does 'grain lines' as a clarity characteristic indicate?
- Irregular crystal growth directions within the diamond (Correct answer)
- Surface polishing lines left by the wheel
- Cracks caused by laser drilling
- Metallic inclusions from the mantle
Correct answer: Irregular crystal growth directions within the diamond
Grain lines result from irregular crystal growth and may appear as faint lines or planes within or on the surface of the diamond.
GIA Diamond Grading & Classification 3
What is the weight in carats of a diamond that weighs 0.20 grams?