Diamond Education
Diamond education is essential to understand the characteristics and quality aspects of diamonds. Through our Diamond education page, we aim to demystify these concepts and explain their influence on buying decisions, with the help of informative articles, guides and videos.
Diamond Polish
& Symmetry
Polish and Symmetry are key elements that have
an impact on diamond quality. Polish and Symmetry
influence a diamond’s cut and affect its appearance and value.
Diamond Polish & Symmetry - An Overview
What Is
Diamond Polish?
Polish is the extent of smoothness and condition of a diamond’s surface after it has been cut and given its facets. A well polished diamond has the ability to transmit light without any distortions and produce crisp reflections, whereas a poorly polished diamond can look dull. While the diamond cutter aims to achieve a beautiful, glass-like finish, a gemologist determines the diamond’s polish grade by looking at the stone under 10x magnification for the presence of any imperfections that may have resulted from the cutter’s work. It is quite challenging to perfectly polish a diamond and leave no remnants of imperfection in the process. Nearly every diamond may be left with blemishes due to human error after it is polished. While the blemishes are usually microscopic and cannot be spotted by the naked eye, at times they can noticeably affect the visual appearance of the diamond.
Polish Marks
On A Diamond
Polish marks are superficial and do not penetrate the diamond’s surface. They are hence graded separately and not as clarity attributes. Common polish marks are: Scratch – Transparent looking white line on the diamond’s surface. Nick – Minute notches found on facet or girdle junctions. Abrasion – Series of nicks at facet junctions. Pit – A small opening caused by inclusions falling out during polishing. Skin bumps – Bumpy, uneven texture on the diamond’s surface. Polish lines – Parallel fine lines that may appear white or translucent. Rough girdle – An unpolished girdle left in its original state. Burn marks – Whitish haze caused by high temperature from a cutting torch or polishing wheel.
Diamond Polish Grade
Recommendations
Diamonds having a polish grade of Excellent, Very Good and Good are all optimum, as any polishing flaws would not be visible to the naked eye. The miniscule flaws in these polish grades do not have an impact on the diamond's overall appearance. For diamonds with clarity grades of I1 or lower, a polish grade of Fair is acceptable since these diamonds already possess internal inclusions that are visible to the naked eye, rendering any polish markings less relevant. For diamonds less than .75 carats, polish grades of Fair or higher will not affect the appearance of the diamond to an inexperienced viewer. Diamonds with Poor polish grades should be avoided, as their only saving grace is to have them re-cut or re-polished.
What Is Diamond
Symmetry?
Symmetry refers to the alignment of the facets of a diamond. A diamond’s symmetry grade is determined by the presence and visibility of symmetry deviations at 10x magnification. An ideal symmetry is achieved when the top of a diamond (crown) is in perfect alignment with the diamond’s bottom (pavilion) where they meet at the girdle. When cutting the facets of a diamond, the goal of a cutter is to get maximum value out of the rough stone. Hence, cutting is a carefully planned activity. After the cutting process, any facets that remain misaligned are left on purpose to either retain some of the diamond’s carat weight or to remove inclusions. Common symmetry variations may include unequal crown angles, an off-center culet, extra facets, variation in girdle thickness, missing facets, unequal pavilion angles etc. To receive the highest grade for symmetry, diamonds must have the correct number of facets and display virtually no symmetry variations.
Diamond
Symmetry Grade
Recommendations
Diamonds that have a good grading in other parameters would essentially have a symmetry grade of Excellent, Very Good or Good. It is important to have Excellent, Very Good or Good symmetry in diamonds of VVS2 Clarity and higher, since the subtle defects highlighted by Fair or Poor symmetry would compromise the diamond's otherwise flawless appearance. Diamonds with Poor symmetry have defects visible to the naked eye and hence should be avoided in all cases.
How Important Are A Diamond’s Polish And Symmetry?
Diamond Symmetry and Polish are graded just like the Cut aspect, and hence are instrumental in determining a diamond’s appearance and value. Polish and symmetry influence cut grade, which in turn affects carat weight, and these have the greatest impact on a diamond’s price. So much so, that a diamond with ‘Excellent’ Symmetry and Polish may be priced 10%-15% higher than a diamond with ‘Good’ Symmetry and Polish. The difference between a 1-carat diamond and a 0.99-carat diamond is most likely to happen during a polish, thereby impacting the value. Besides Symmetry and Polish though, there are other factors that have just as much or even more influence on a diamond’s appearance and cut, like table and depth percentage. Hence, knowing what is diamond polish and symmetry, and considering these factors greatly help a buyer in selecting a beautiful diamond that’s worth it’s cost.
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