GIA Diamond Grading & Classification 3

Question 1

What is the weight in carats of a diamond that weighs 0.20 grams?

Accepted Answer

1.00 ct

Answer

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?

Accepted Answer

SI1

Answer

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?

Accepted Answer

Fire

Answer

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?

Accepted Answer

A small fracture or crack within the diamond

Answer

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?

Accepted Answer

G, H, I, J

Answer

GIA classifies G through J as 'Near Colorless,' a range where color is difficult to detect without comparison stones.

(GIA) Certified Diamonds Gemological Institute of America Practice Test