What does polish mean in jewellery and diamonds?
By Jared James · Last updated 21 May 2026
Definition
In jewellery, polish refers to two related things. For metal, it describes the smooth, highly reflective finish achieved by working through progressively finer abrasives until the surface mirrors light cleanly. For diamonds and gemstones, polish is one of the five factors GIA uses to grade a cut stone's quality, measuring how smoothly each facet surface was finished by the cutter. A polish grade of Excellent or Very Good means the facets are crisp and clean, while lower grades indicate marks left by the polishing wheel that can slightly reduce brilliance.
Frequently asked questions
- Does diamond polish affect sparkle?
- At the top grades, Excellent and Very Good, the effect on everyday appearance is minimal. At Fair or Poor, polishing lines or surface marks can slightly scatter light and reduce the stone's brightness, though the impact is usually subtle compared to cut proportions.
- What is the best polish grade for a diamond?
- GIA grades polish as Excellent, Very Good, Good, Fair or Poor. Excellent is the top grade, but Very Good is also considered fine and often costs less without any visible difference. Most jewellers recommend choosing at least Good for a well-finished stone.
- Can tarnished jewellery be re-polished?
- Yes, a jeweller can buff metal back to a bright polish using a polishing wheel, and you can maintain it at home with a jewellery polishing cloth for regular upkeep. Deep scratches need professional attention, but surface dullness is easy to remove.
Designing a ring
Talk through polish with us
Tell us what you have in mind, even if it is only a budget and a piece of jewellery type, and we will help you weigh up the options. We reply to every enquiry, usually within one business day.
Contact the studio