GIA Diamond Grading & Classification 4

Question 1

Which proportional element most directly affects a round brilliant diamond's light return or 'brilliance'?

Accepted Answer

Pavilion angle

Answer

The pavilion angle is the most critical factor in total internal reflection, which drives the amount of white light returned to the viewer's eye.

Question 2

A GIA Diamond Grading Report describes a stone as 'Fancy Intense Yellow.' This notation refers to the diamond's:

Accepted Answer

Color beyond the D-to-Z scale

Answer

Diamonds with color saturation beyond Z, or with hues such as yellow, pink, or blue, receive GIA Fancy Color grades with descriptors like Faint, Very Light, Light, Fancy Light, Fancy, Fancy Intense, or Fancy Vivid.

Question 3

What is the purpose of the 'plotting diagram' on a GIA Diamond Grading Report?

Accepted Answer

To map the location and type of clarity characteristics within the stone

Answer

The plotting diagram is a schematic of the diamond's facets showing the exact position and nature of each inclusion and blemish used to assign the clarity grade.

Question 4

Under GIA standards, which clarity grade indicates that inclusions are obvious under 10x magnification and may affect transparency or brilliance?

Accepted Answer

I1

Answer

I1 (Included 1) diamonds have inclusions obvious under 10x magnification that may impact brilliance and are often visible to the naked eye.

Question 5

A diamond's 'star length' proportion refers to the length of which set of facets?

Accepted Answer

Star facets on the crown extending from the table

Answer

Star facets are the eight triangular facets on the crown that radiate from the corners of the table, and their length ratio affects light dispersion.

(GIA) Certified Diamonds Gemological Institute of America Practice Test

(GIA) Certified Diamonds Gemological Institute of America Practice Test

GIA Diamond Grading & Classification 4