Diamond Grading and Identification Flashcards

Which of the following best describes a 'pinpoint' inclusion in a diamond?

Answer: A tiny white or black dot visible under magnification

A pinpoint is a minute crystal inclusion that appears as a tiny dot when viewed under magnification.

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

Answer: To show the diamond's actual proportions in a schematic cross-section

The proportion diagram provides a schematic cross-section of the diamond illustrating its measured proportions.

When grading diamond color, GIA graders view the stone:

Answer: Table-down against a white background using north daylight-equivalent light

GIA color grading is performed table-down (pavilion-up) against a white background under controlled, north daylight-equivalent light.

A 'bearding' blemish on a diamond refers to:

Answer: Tiny feathers extending inward from the girdle, creating a fuzzy appearance

Bearding consists of minute feathers extending from the girdle into the stone, often caused by bruting.

Which GIA clarity grade range is considered 'eye-clean' for most diamonds?

Answer: FL to SI2

Diamonds graded FL through SI2 are generally considered eye-clean, meaning inclusions are not visible to the unaided eye.

What does 'dispersion' produce in a diamond?

Answer: The separation of white light into spectral colors (fire)

Dispersion separates white light into its spectral colors, creating the rainbow flashes known as 'fire' in a diamond.

On a GIA Diamond Grading Report, 'clarity characteristics' are plotted on which diagram?

Answer: A face-up diagram and a pavilion-view diagram

GIA uses both a face-up (crown) and pavilion-view diagram to map the position of inclusions and blemishes.