Prefinishing, Polishing and Buffing

Quality Assurance Benchmarks highlight workmanship of semi-finished or finished jewelry. Learn how to evaluate the quality of a platinum ring that has been prefinished, polished, and buffed.

Side and perspective views of a four-prong, platinum solitaire

Exhibits a natural, bright-white platinum luster, and no fine scratches are visible to the unaided eye

Evenly shaped and contoured

Free of tool marks

Free of debris

Does not show pitting or porosity

Original ring dimensions (shank width and depth) are accurate

Side and perspective views of four-prong, platinum solitaires with diamonds in the shank. The quality mark of “950 Pt/Ru” is visible in the perspective view, indicating that this ring was made using an alloy of platinum ruthenium

Free of tool marks

Hallmarking is appropriately placed and readable

No parting lines or unfinished areas

Does not show pitting or porosity

Original ring dimensions (shank width and depth) are accurate

Polishing and Buffing

Tools and Techniques for Polishing and Buffing Platinum

Jeweler polishing a platinum ring at a polishing machine.

Polishing: Using a variety of wheels and compounds to remove very fine scratches gradually, and smooth and brighten a platinum piece

Buffing: Using a variety of wheels and compounds to remove ultra-fine scratches gradually, and obtain a superior bright-white, high-platinum luster

Tool marks are removed during prefinishing. When prefinished, the piece has very fine surface scratches, which will be removed by polishing.

The final quality achieved by platinum polishing and buffing is possible only with proper burnishing and prefinishing. If a platinum piece has been poorly burnished and prefinished, a bright-white, high-platinum luster cannot be achieved.

Achieving the best results

Two yellow-treated wheels labeled “800” and “1500,” and three white wheels labeled “4000,” “6000,” and “8000,”indicating the abrasive grades of the platinum polishing compounds placed on top of the wheels,

To polish and buff platinum, multiple steps and grades of abrasive compounds are required. The two yellow-treated wheels shown here are labeled “800” and “1500,” which indicates their abrasive grades. They are ideal for polishing.

The quality achieved by platinum polishing and buffing is possible only with proper burnishing and refinishing. If a platinum piece has been poorly burnished and prefinished, it is impossible to achieve a bright-white, high-platinum luster.

Platinum compounds are evenly blended and adhere well to buffs, brushes, and felt attachments. The abrasive grades of platinum compounds range from 800 to 8000.

Not shown, but also used for polishing platinum, are hard felt wheels known as laps or split laps. Laps are commonly used for polishing crisp edges and flat surfaces.

Avoiding Cross-Contamination

A jeweler placing a yellow platinum polishing wheel labeled “800” and compound into an individual storage bag also labeled “800”

Cross-contamination is highly detrimental to the polishing process. To avoid cross-contamination, label each wheel and compound. Individual storage and color coding is also suggested.

The 800 polishing compound grade is almost twice as course as 1500 compound. Because of this, isolate the compound and the wheels.

Polishing Platinum

A jeweler preparing to polish a platinum ring using the yellow-treated wheel labeled “800”

For polishing, the piece must be completely free of deep scratches, tool marks, and other visible blemishes. Proper prefinishing is critical.

Polishing wheels are available in a wide assortment of styles and sizes. As a general rule, the larger the wheel, the faster its speed at the contact point.

For platinum polishing, stitched and treated buffs are most effective. Unstitched buffs are too soft and will round all edges. Their softness cannot create necessary pressure and friction at the contact point, so polishing will take longer.

Polishing at the Bench

A jeweler using a smaller wheel to polish a platinum ring at the bench

Some platinum polishing applications can be done at the bench using smaller stitched and treated buffs and laps. Again, proper prefinishing is mandatory.

Polishing at the bench can be quick and efficient: Generally, larger wheels are faster, but small jobs like ring sizing can be polished at the bench

Tray containing five compartments of platinum polishing compound in various grits, along with five adjacent compartments containing attachments for working with the compound at the bench

For polishing at the bench, keep a small polishing and buffing compound and wheel attachment kit handy. Make sure that all compounds are labeled and multiple wheels and laps are available to prevent cross-contamination.

Polishing Inside Settings

Jeweler holding the setting of a four-prong, platinum solitaire with no center stone. The inside of the setting is visible.

The area inside a prong or bezel setting area is often overlooked during prefinishing and polishing. Prefinishing and polishing inside a setting takes little time, and adds value to the piece.

Polishing inside the setting will make it easier to clean away debris that accumulates during normal wear, and will also create a brighter and whiter appearance under the center diamond

Buffing Platinum: Achieving the Best Results

Jeweler finishing the four-prong, platinum solitaire on the 4000 grit abrasive wheel

Use all three grades of compound (4000, 6000, and 8000), and their accompanying wheels for the finest finish. Clean jewelry between each grit change to prevent cross-contamination.

Buffing, when done after proper prefinishing and polishing, will brighten platinum jewelry and give it the unmistakable bright white luster

No shaping, tool mark removal, or refinement of deep scratches is possible through buffing – only the removal of ultra-fine scratches and the creation of a high luster. As is the case with prefinishing and polishing, cross-directional buffing will yield the best results.