GIA Diamond Grading and Identification 3 — Questions and Answers
Question 1: Which of the following best describes a 'pinpoint' inclusion in a diamond?
- A tiny white or black dot visible under magnification (Correct answer)
- A long fracture extending from the surface to the interior
- A white hazy area caused by many tiny inclusions
- A surface chip along the girdle edge
Correct 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.
Question 2: What is the purpose of a 'proportion diagram' on a GIA Diamond Grading Report?
- To show the diamond's actual proportions in a schematic cross-section (Correct answer)
- To map the location of all inclusions and blemishes
- To illustrate the diamond's color relative to the master set
- To display the diamond's fluorescence intensity under UV light
Correct 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.
Question 3: When grading diamond color, GIA graders view the stone:
- Table-down against a white background using north daylight-equivalent light (Correct answer)
- Table-up under direct halogen illumination
- Pavilion-up under fluorescent lighting
- Face-up under UV light to detect fluorescence
Correct 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.
Question 4: A 'bearding' blemish on a diamond refers to:
- Tiny feathers extending inward from the girdle, creating a fuzzy appearance (Correct answer)
- Polish lines left on the facet surface
- A surface abrasion caused by contact with other diamonds
- A flat cleavage crack running parallel to the girdle
Correct 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.
Question 5: Which GIA clarity grade range is considered 'eye-clean' for most diamonds?
- FL to SI2 (Correct answer)
- I1 to I3
- IF only
- VVS1 to VVS2 only
Correct answer: FL to SI2
Diamonds graded FL through SI2 are generally considered eye-clean, meaning inclusions are not visible to the unaided eye.
Question 6: What does 'dispersion' produce in a diamond?
- The separation of white light into spectral colors (fire) (Correct answer)
- The reflection of light off the diamond's surface (luster)
- The diamond's overall brilliance and brightness
- The scattering of light within the diamond
Correct 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.
Question 7: On a GIA Diamond Grading Report, 'clarity characteristics' are plotted on which diagram?
- A face-up diagram and a pavilion-view diagram (Correct answer)
- A proportion diagram only
- A fluorescence color chart
- A girdle outline sketch
Correct 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.
GIA Diamond Grading and Identification 3
Which of the following best describes a 'pinpoint' inclusion in a diamond?