A lens cleaning cloth is a bench supply used to remove dust, fingerprints and oily films from optical surfaces - loupe lenses, microscope objectives, refractometer windows, polariscope filters - and from the table and pavilion of finished gemstones during examination, sorting and presentation. The standard material is a tightly woven microfibre, typically a 70/30 polyester-polyamide blend, which traps particulate without abrading polished surfaces. Traditional chamois leather cloths and lint-free cotton flannel are also used, particularly for final polishing of optical glass.

For gem work, the cloth should be reserved for the bench and not used to wipe the lab floor or general surfaces, because grit picked up from contaminated cloth will scratch a stone. A clean microfibre will remove the bench oils, finger oils and shop dust that interfere with refractometer readings, microscope clarity and visual colour grading. A small amount of optical-grade lens cleaning fluid or distilled water can be used for stubborn smudges; never use facial tissue or paper towel on a polished gem surface, as wood-fibre paper carries microscopic abrasive that will leave fine scratches over time.

The cloth should be laundered periodically without fabric softener, which deposits a film that defeats the cleaning function. A pack of three or four cloths rotated through use and laundering is standard at the gem-trade bench.