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

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

Exhibits a natural, bright-white platinum lustre, 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

Jeweller polishing a platinum ring at a polishing machine.

Polishing: Using a variety of wheels and compounds to gradually remove very fine scratches, and to 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 lustre

Tool marks are removed during pre-finishing. When pre-finished, the piece has very fine surface scratches, which will be removed by polishing.

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

Achieving the best results 

Two yellow-treated wheels labelled “800” and “1500”, and three white wheels labelled “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 labelled “800” and “1500”, which indicates their abrasive grades. They are ideal for polishing.

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

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 jeweller placing a yellow platinum polishing wheel labelled “800” and compound into an individual storage bag also labelled “800”

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

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

Polishing Platinum 

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

For polishing, the piece must be completely free of deep scratches, tool marks and other visible blemishes. Proper pre-finishing 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 the necessary pressure and friction at the contact point, so polishing will take longer.

Polishing at the Bench

A jeweller 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 pre-finishing 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 labelled and multiple wheels and laps are available to prevent cross-contamination.

Polishing Inside Settings

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

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

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

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 centre diamond

Buffing Platinum: Achieving the Best Results

Jeweller 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 jewellery between each grit change to prevent cross-contamination.

Buffing, when done after proper pre-finishing and polishing, will brighten platinum jewellery and give it the unmistakable bright white lustre

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 lustre. As is the case with pre-finishing and polishing, cross-directional buffing will yield the best results.

Buffing Inside Settings   

Jeweller holding a platinum band at the bench, in preparation for buffing

For certain applications, buffing at the bench will save time, and the results are just as effective

Featured Quality Assurance Benchmarks

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