GIA Diamond Proportions & Cut Analysis 2

Question 1

What is 'brilliance' in the context of diamond light performance?

Accepted Answer

The white light reflected from the interior and exterior of a diamond

Answer

The colored spectral light dispersed from within a diamond

Answer

The flashes of light seen when the diamond or light source moves

Answer

The glow produced by a diamond's fluorescence under UV light

Question 2

Which term describes the dispersion of white light into spectral rainbow colors in a diamond?

Accepted Answer

Fire

Answer

Brilliance

Answer

Scintillation

Answer

Luster

Question 3

How does an excessively deep (steep) pavilion angle affect the light performance of a round brilliant diamond?

Accepted Answer

It causes light to leak through the pavilion sides rather than reflecting back through the crown

Answer

It causes light to reflect too quickly, creating excessive fire

Answer

It makes the diamond appear larger than its actual carat weight

Answer

It enhances scintillation by multiplying light flash points

Question 4

What is the 'fisheye' effect in a diamond?

Accepted Answer

A reflection of the girdle visible through the table caused by a too-shallow pavilion

Answer

An inclusion pattern that resembles a fish eye when viewed under magnification

Answer

The appearance of the culet when viewed face-up through the table

Answer

A special faceting arrangement used in some fancy-shape diamonds

Question 5

What is 'scintillation' in diamond light performance?

Accepted Answer

The pattern of light and dark areas plus flashes of reflected light when the diamond or viewer moves

Answer

The total white light returned from a diamond's interior and exterior

Answer

The dispersion of white light into its spectral colors

Answer

The brightness of a diamond's fluorescence under ultraviolet light

Question 6

Which crown angle range is generally associated with optimal light performance in round brilliant diamonds according to GIA research?

Accepted Answer

34–35°

Answer

15–20°

Answer

25–30°

Answer

40–45°

Question 7

What does 'light leakage' indicate in a diamond cut assessment?

Accepted Answer

Light exits through the pavilion or sides without being reflected back to the observer

Answer

Light is over-reflected from the crown facets creating glare

Answer

Light is absorbed by internal inclusions reducing overall brightness

Answer

Light disperses into too many spectral colors reducing white light return