Polished Girdle
Polished Girdle
A diamond girdle finished smooth rather than left bruted or cut into facets
A polished girdle is a diamond girdle that has been finished to a smooth surface rather than left in the bruted (frosted) state or cut into facets. Under magnification, the polished girdle appears as a continuous translucent band running around the perimeter of the stone, with no visible facet pattern and a glossy rather than matte finish. The polished girdle is one of three standard girdle finishes recognised by GIA and other diamond grading laboratories, alongside the bruted and faceted girdles.
How it is produced
The girdle is the band where the upper crown facets meet the lower pavilion facets, and it is the part of the diamond most often handled by the setter when mounting the stone. In modern cutting, the girdle is first bruted into a rough cylindrical surface, then either left bruted, polished smooth, or cut into a series of small facets. Polishing the girdle requires a separate operation on a lap, working the bruted surface down to a clean translucent band that no longer scatters light.
Why finishing choice matters
Each girdle finish has practical consequences. A bruted girdle, with its frosted appearance, hides minor surface defects and is the easiest to produce, but the matte texture is sometimes mistaken for a fracture or natural cleavage at first inspection. A faceted girdle, with small triangular facets running around the perimeter, presents a polished and uniform appearance and provides better light reflection, and is the standard finish on modern premium round-brilliant diamonds. A polished girdle sits between the two: cleaner than bruted, simpler than faceted, and somewhat less common in current production.
For setters, the polished girdle is workable but offers slightly less grip for prong settings than a bruted girdle, where the matte texture provides additional friction. For graders, the polished girdle's continuous appearance makes irregularities more visible than they would be on a faceted finish, and a poorly polished girdle can drag the overall polish grade down.
Where the polished girdle appears
Polished girdles are most often encountered on older cuts, on stones from cutting traditions that did not adopt faceted-girdle production, and occasionally on contemporary cuts where the cutter or buyer has specifically requested the finish. The fancy-shape market shows somewhat more variation in girdle finish than the round-brilliant market does. GIA reports note the girdle finish — bruted, polished, or faceted — and the grader's observation of any irregularities along the band.
In the trade
The girdle finish does not significantly affect retail price on its own, but it is part of the overall workmanship picture that experienced buyers consider. A faceted girdle on a modern round brilliant signals contemporary cutting practice; a polished girdle is more often a marker of an older or specialised cutting tradition. Buyers reading a grading report for an individual stone will typically check the girdle thickness and finish notation alongside polish and symmetry as part of the overall assessment.