1
GIA DIAMONDS AND DIAMOND GRADING
FINAL EXAM NEWEST 2025-2026 ACTUAL EXAM
COMPLETE 100 QUESTIONS AND CORRECT
DETAILED ANSWERS (VERIFIED)
1.
A client presents a round brilliant diamond for evaluation. Under standard daylight-equivalent
lighting, the diamond appears colorless. However, when observed under UV light, the diamond
displays strong blue fluorescence. The color grade is G, and the clarity is VS1. The client asks
whether the fluorescence will impact the diamond’s market value. As a gemologist, you must
assess both the grading report and market trends. Taking into account GIA's official stance on
fluorescence and known buyer behavior, how should you advise the client regarding the
influence of strong blue fluorescence on diamonds in the near-colorless color range?
A. Fluorescence will improve the color grade
B. Fluorescence has no effect on any diamonds
C. Fluorescence decreases the clarity grade
D. Fluorescence may reduce value slightly in high-color grades
✅ Correct Answer:
D. Fluorescence may reduce value slightly in high-color grades
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📘 Rationale:
Strong blue fluorescence can occasionally make a diamond appear hazy or oily, especially in
higher color grades like D through G. While GIA emphasizes that fluorescence does not
influence the color or clarity grade directly, market perceptions often do. Buyers may devalue
stones with strong fluorescence even if they appear fine in most lighting. It is important to
explain to clients that fluorescence is disclosed on GIA grading reports and that its impact is
subjective and often minor but market-relevant.
📚 Reference:
GIA (2021). Diamonds and Diamond Grading Course Materials. Gemological Institute of
America.
2.
During a diamond grading session, you observe that a round brilliant diamond displays
extremely narrow and uneven girdle thickness under 10x magnification. The diamond has
excellent polish and symmetry but shows durability risks due to the girdle. The client asks how
this will affect the final cut grade and whether it could lower the overall value. As a trained
gemologist, which factor should you consider when assigning the GIA cut grade and advising the
client about possible long-term wear issues with girdle proportions in relation to durability and
aesthetics?
A. Girdle thickness does not affect cut grade
B. Only polish affects cut grading
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C. Uneven girdle can lower cut grade and durability
D. Extremely thin girdles are ideal for light return
✅ Correct Answer:
C. Uneven girdle can lower cut grade and durability
📘 Rationale:
An extremely thin or uneven girdle is considered a durability risk, especially if the diamond is
set in a ring subject to daily wear. It can also impact the cut grade assigned by GIA, as girdle
thickness is a part of proportion grading. While polish and symmetry are separate components,
the cut grade accounts for proportions, symmetry, and polish collectively. Uneven or extremely
thin girdles may also increase the risk of chipping, especially near pointed edges or during
setting.
📚 Reference:
GIA (2021). Diamonds and Diamond Grading Course Materials. Gemological Institute of
America.
3.
You are evaluating a 1.00-carat round brilliant diamond with VS2 clarity and F color. Under 10x
magnification, you identify a feather located near the girdle edge. The feather is white and does
not appear surface-reaching. The client asks if the clarity grade should be lowered due to the
inclusion’s location. As a GIA-trained gemologist, what considerations must you apply when
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determining whether this feather will affect durability or downgrade the clarity grade, especially
if it’s close to a vulnerable facet?
A. Any inclusion lowers clarity to SI
B. Feather location and visibility under 10x magnification determine impact
C. Feathers are never considered clarity factors
D. Internal features near girdle are not graded
✅ Correct Answer:
B. Feather location and visibility under 10x magnification determine impact
📘 Rationale:
GIA’s clarity grading is based on number, size, location, nature, and relief of inclusions under
10x magnification. A small, internal feather near the girdle that is not surface-reaching typically
does not lower clarity from VS2, especially if it’s not visible face-up. However, if located at a
structurally vulnerable area (e.g., near a thin girdle or culet), it may raise concerns about
durability, even if it doesn’t change the clarity grade. The gemologist must evaluate both
technical clarity and wearability concerns.
📚 Reference:
GIA (2021). Diamonds and Diamond Grading Course Materials. Gemological Institute of
America.
4.
GIA DIAMONDS AND DIAMOND GRADING
FINAL EXAM NEWEST 2025-2026 ACTUAL EXAM
COMPLETE 100 QUESTIONS AND CORRECT
DETAILED ANSWERS (VERIFIED)
1.
A client presents a round brilliant diamond for evaluation. Under standard daylight-equivalent
lighting, the diamond appears colorless. However, when observed under UV light, the diamond
displays strong blue fluorescence. The color grade is G, and the clarity is VS1. The client asks
whether the fluorescence will impact the diamond’s market value. As a gemologist, you must
assess both the grading report and market trends. Taking into account GIA's official stance on
fluorescence and known buyer behavior, how should you advise the client regarding the
influence of strong blue fluorescence on diamonds in the near-colorless color range?
A. Fluorescence will improve the color grade
B. Fluorescence has no effect on any diamonds
C. Fluorescence decreases the clarity grade
D. Fluorescence may reduce value slightly in high-color grades
✅ Correct Answer:
D. Fluorescence may reduce value slightly in high-color grades
,2
📘 Rationale:
Strong blue fluorescence can occasionally make a diamond appear hazy or oily, especially in
higher color grades like D through G. While GIA emphasizes that fluorescence does not
influence the color or clarity grade directly, market perceptions often do. Buyers may devalue
stones with strong fluorescence even if they appear fine in most lighting. It is important to
explain to clients that fluorescence is disclosed on GIA grading reports and that its impact is
subjective and often minor but market-relevant.
📚 Reference:
GIA (2021). Diamonds and Diamond Grading Course Materials. Gemological Institute of
America.
2.
During a diamond grading session, you observe that a round brilliant diamond displays
extremely narrow and uneven girdle thickness under 10x magnification. The diamond has
excellent polish and symmetry but shows durability risks due to the girdle. The client asks how
this will affect the final cut grade and whether it could lower the overall value. As a trained
gemologist, which factor should you consider when assigning the GIA cut grade and advising the
client about possible long-term wear issues with girdle proportions in relation to durability and
aesthetics?
A. Girdle thickness does not affect cut grade
B. Only polish affects cut grading
,3
C. Uneven girdle can lower cut grade and durability
D. Extremely thin girdles are ideal for light return
✅ Correct Answer:
C. Uneven girdle can lower cut grade and durability
📘 Rationale:
An extremely thin or uneven girdle is considered a durability risk, especially if the diamond is
set in a ring subject to daily wear. It can also impact the cut grade assigned by GIA, as girdle
thickness is a part of proportion grading. While polish and symmetry are separate components,
the cut grade accounts for proportions, symmetry, and polish collectively. Uneven or extremely
thin girdles may also increase the risk of chipping, especially near pointed edges or during
setting.
📚 Reference:
GIA (2021). Diamonds and Diamond Grading Course Materials. Gemological Institute of
America.
3.
You are evaluating a 1.00-carat round brilliant diamond with VS2 clarity and F color. Under 10x
magnification, you identify a feather located near the girdle edge. The feather is white and does
not appear surface-reaching. The client asks if the clarity grade should be lowered due to the
inclusion’s location. As a GIA-trained gemologist, what considerations must you apply when
, 4
determining whether this feather will affect durability or downgrade the clarity grade, especially
if it’s close to a vulnerable facet?
A. Any inclusion lowers clarity to SI
B. Feather location and visibility under 10x magnification determine impact
C. Feathers are never considered clarity factors
D. Internal features near girdle are not graded
✅ Correct Answer:
B. Feather location and visibility under 10x magnification determine impact
📘 Rationale:
GIA’s clarity grading is based on number, size, location, nature, and relief of inclusions under
10x magnification. A small, internal feather near the girdle that is not surface-reaching typically
does not lower clarity from VS2, especially if it’s not visible face-up. However, if located at a
structurally vulnerable area (e.g., near a thin girdle or culet), it may raise concerns about
durability, even if it doesn’t change the clarity grade. The gemologist must evaluate both
technical clarity and wearability concerns.
📚 Reference:
GIA (2021). Diamonds and Diamond Grading Course Materials. Gemological Institute of
America.
4.
