A polishing stick is a hand-held wooden or plastic shaft, typically a few millimetres thick and shaped at one end into a flat or rounded face, charged with diamond paste or another fine compound and used for the localised polishing of jewellery surfaces too small or too inaccessible for a wheel or pad. The stick is also called a polishing pencil, and a working bench will carry a row of them in graded grits, each dedicated to a single compound and stored away from contamination.

Construction and charging

The stick is most often turned from a hardwood — boxwood, beech, or birch — selected for a tight grain that holds compound without splintering. Plastic sticks, usually of dense nylon or acetal, are used where the operator wants a slightly more compliant face that conforms to a curved surface. The working face is shaped to the job: flat for facet edges, rounded for prong tips, knife-edged for the inside of a bezel wall or the line between two surfaces.

The stick is charged by working diamond paste into the wood with a thumb or by drawing it across a compound bar. A correctly charged stick darkens visibly as the abrasive embeds in the surface; over time the working face glazes and is refreshed by sanding back to fresh wood.

Use cases

Polishing sticks are the standard tool for finishing prong tips after stone setting, where a wheel would catch the stone or round over the prong. They are used to polish the inside walls of a bezel, the underside of a finished setting, and the thin metal between two stones in a pavé or channel-set arrangement. A skilled bench worker uses a stick to put a final lustre on the visible surfaces of a setting after the stones are mounted and any wheel work has been completed at distance from the stones.

Sticks are also used on the stone itself for selective touch-up, particularly on facet edges or on a small chip that has been re-cut by hand and needs a final polish without disturbing adjacent facets. Diamond compounds in the 1- to 14-micron range are the standard charge for facet touch-up; rouge or chromium oxide is used for metal work.

In the trade

The polishing stick belongs to the same category of small bench tools as the burnisher and the riffler file: tools that finish what the larger machines cannot reach. A polishing stick costs almost nothing to make and lasts for years if the working face is refreshed periodically. Most bench jewellers maintain a personal set, shaped over time to the kinds of work they do most often.

Further reading

• International Gem Society — bench finishing tools
• GIA Gems & Gemology — bench technique
• GIA Gem Encyclopedia — finishing methods