Diamond polish grading refers to the assessment of the smoothness of the diamond's facets and the clarity of its surface. A well-polished diamond better reflects light, maximising its brilliance. This guide delves deep into the intricacies of diamond polish grading.

The Importance of Diamond Polish

A well-polished diamond:

• Reflects light more effectively.
• Displays better fire and brilliance.
• Presents a cleaner, more appealing aesthetic.

Factors Affecting Diamond Polish

Rough Diamond Quality

Inherent flaws or inclusions in a rough diamond can affect the polishing outcome.

Polishing Techniques & Equipment

The quality of the tools and techniques used can produce varying levels of polish on a diamond.

Skill of the Diamond Polisher

The experience and skill level of the polisher play a significant role in the diamond's final polish.

Diamond Polish Grading Scale

Most diamond grading entities, like the GIA (Gemological Institute of America), use a grading scale for polish:

1. Excellent (EX): No or negligible polish defects visible under 10x magnification. Excellent brilliance and light return.
2. Very Good (VG): Minor polish defects visible under 10x magnification. They do not typically affect the diamond's visual appeal to the naked eye.
3. Good (G): Noticeable polish defects under 10x magnification, but these usually don't diminish the diamond's fire and brilliance to the unaided eye.
4. Fair (F): Defects may be visible to the naked eye and might slightly reduce the diamond's brilliance.
5. Poor (P): Major defects visible to the unaided eye, significantly reducing the diamond's brilliance and appeal.

Common Diamond Polish Imperfections

Polish Lines

Fine lines on the diamond's surface. They often result from polishing the diamond against its grain.

Surface Graining

These are minute, almost invisible lines on the diamond's surface, resulting from its crystal structure.

Clouds

These are hazy areas on the diamond, often a collection of minute inclusions.

Scratches

Visible marks or grooves on the diamond's surface, typically from mishandling.

Pits

Tiny indentations on the diamond's surface.

Burns

Caused by excessive heat during polishing. They appear as milky white patches.

Importance of Balanced Grading

While polish is crucial, it should be viewed in conjunction with other factors like the diamond's cut, clarity, and symmetry. A diamond with excellent polish but poor symmetry might not be as valuable as one with good polish and excellent symmetry.

Care and Maintenance

• Avoid wearing diamonds during rough work.
• Clean diamonds regularly using mild detergent and a soft brush.
• Always store diamonds separately to prevent scratches.

A diamond's polish is an integral part of its overall beauty and value. Recognising the importance of polish grading helps consumers and traders alike to make informed decisions about their diamonds. Whether you're a seasoned jeweler or a novice consumer, understanding polish grading can guide you toward the best choices for your needs and preferences.