Gemology Certification Gemology Gemstone Grading & Evaluation 2

Question 1

Which grading system uses terms like 'Loupe Clean' and 'Piqué' for clarity grades?

Accepted Answer

CIBJO system

Answer

CIBJO (the World Jewellery Confederation) uses terminology such as Loupe Clean (LC) and Piqué (P1–P3) in its gemstone grading nomenclature.

Question 2

A ruby exhibits strong red fluorescence under long-wave UV. How does this typically affect its value?

Accepted Answer

It can enhance apparent color and increase value

Answer

Strong red fluorescence in rubies can intensify the perceived red color in daylight, often increasing desirability and market value.

Question 3

When grading a fancy-shape diamond, which proportion is most critical for assessing its length-to-width ratio?

Accepted Answer

L/W ratio

Answer

The length-to-width (L/W) ratio determines the visual outline and appeal of fancy-shape diamonds, directly influencing their market desirability.

Question 4

In colored stone grading, 'tone' refers to which quality of color?

Accepted Answer

The degree of lightness or darkness of the color

Answer

Tone describes how light or dark a color appears, ranging from very light to very dark on a grading scale.

Question 5

Which treatment in emeralds is considered standard trade practice and must still be disclosed?

Accepted Answer

Cedar oil or resin filling

Answer

Cedar oil and resin filling of surface-reaching fractures is a widely accepted trade practice for emeralds but still requires disclosure due to its impact on durability and value.

Gemology Certification Practice Test

Gemology Certification Practice Test

Gemology Certification Gemology Gemstone Grading & Evaluation 2