About tarnishing & plating

Silver tarnishes. Not because it is low quality, but because it is silver — it reacts with sulphur compounds in ordinary air to form silver sulphide, a dark film on the surface. Every silver jewelry brand is therefore in the business of managing an inevitable chemical reaction, and the treatment you specify determines whether your customer sees a piece that stays bright for three years or one that goes grey in three months.

This guide covers the surface treatments available for sterling silver.

What Tarnish Actually Is

Tarnish is not oxidation in the way rust is. Silver reacts primarily with hydrogen sulphide and other sulphur compounds present in air, in some foods, in wool, in rubber bands, and notably in human sweat — which is why the same piece tarnishes at different rates on different customers.

Two consequences follow. First, tarnish is a surface film, not corrosion of the metal, and polishing genuinely removes it rather than merely hiding it. Second, anything that physically separates the silver from the air slows or stops the process. Every treatment below is a version of that separation.

Rhodium Plating

Rhodium is a platinum-group metal, extremely hard, brilliantly white, and chemically inert. Electroplating a thin layer over sterling silver produces a surface that does not tarnish, resists scratching better than silver, and reads slightly whiter and brighter than polished silver alone.

Rhodium is a wear layer, not a permanent state. On a ring worn daily it may show through in a year or two. This is normal, it is not a defect, and it is worth saying so on your product page rather than leaving the customer to discover it.

E-Coating

Electrophoretic coating deposits a clear polymer lacquer over the entire piece using an electric current. It seals the surface against air completely, including recessed areas that plating reaches poorly, and it costs a fraction of rhodium.

Its advantages are real: complete coverage, very low cost, and it can be applied over plated or unplated silver as a final protective step.

Its limitations are equally real. E-coating is a polymer, and polymers can yellow with UV exposure over time. It can chip on high-wear edges, and a chipped coating tarnishes in a patch, which looks worse than uniform tarnish. It also very slightly softens the surface reflectivity — a difference most customers will not notice but that a jeweller will.