How to distinguish silver from cupronickel and stainless steel

In brief: Sterling silver 925 is distinguished from cupronickel and steel by its hallmark ("925", "Sterling"). A magnet is unreliable, as both silver and cupronickel are non-magnetic. Over time, silver tarnishes evenly, while cupronickel tarnishes unevenly, revealing yellow metal. A green mark on the skin indicates copper, and a reliable home test is a drop of silver nitrate.

Cupronickel can look identical to silver. In photos – exactly. In hand – almost too. The difference emerges after a few months, when the plating begins to wear off in areas of friction or when the jewelry leaves a green mark on the skin.

Here's how to check before purchasing.

Hallmark — the simplest way

Genuine sterling silver 925 has a hallmark. Usually, it's "925", "Sterling", or "Ster". On rings, look inside; on earrings, on the clasp or post; on necklaces, on the clasp. The hallmark is small, sometimes requiring a magnifying glass.

Absence of a hallmark isn't always a sign of a fake. Small items are sometimes not hallmarked due to size. But if there's no hallmark, everything else needs to be checked more carefully.

Magnet

Stainless steel can be magnetic or non-magnetic, depending on the alloy grade. Both silver and cupronickel are non-magnetic. Therefore, a magnet will only rule out some steel fakes but won't tell you anything about cupronickel.

A useful, but not decisive, test.

Color and hue

Sterling silver 925 has a slightly warm white color. Not perfectly cool, not gray. Stainless steel is usually cooler and more matte. Rhodium-plated cupronickel can look brighter and "cheaper shiny" than silver.

This is subjective and depends on the surface finish. Relying solely on color is not advisable.

Behavior over time

Silver tarnishes evenly, forming a patina across the entire surface. Cupronickel tarnishes unevenly: the plating wears off on raised areas and in places of constant contact with the skin, revealing yellowish or pinkish metal underneath.

Stainless steel hardly tarnishes or oxidizes, which sometimes gives it away, as it looks "too stable" even after years without any care.

Skin mark

A green or black mark on the finger from a ring is a sign of copper in the alloy. Sterling silver 925 also contains copper (7.5%), but in a good alloy, this effect is minimal under normal conditions. If the mark appears immediately and constantly, it's most likely cupronickel or a low-grade alloy.

Nitrate test

A reliable home method is a drop of silver nitrate (sold in pharmacies). It reacts weakly with silver, leaving a creamy or gray mark. On copper alloys, it leaves a bright green mark. However, this test leaves a stain on the item.

Price as a signal

A handmade silver ring with gemstones cannot cost 150 hryvnias. If the price is suspiciously low, either the material is wrong, or the stones are not genuine, or both. The market is transparent: the cost of silver and normal production has a certain lower limit.

All SIERRA SPACE jewelry is made from verified sterling silver 925 with the appropriate hallmark.

Frequently Asked Questions

Is cupronickel harmful to the skin?

By itself, no. But nickel, which is often part of cupronickel, is an allergen for some people. If there's a reaction to "silver" jewelry without a hallmark, it's worth checking the composition.

Can metals be distinguished by smell?

Stainless steel has no smell. Silver, too. Cupronickel and brass can give off a faint metallic smell from rubbing against the skin, but this is an unreliable indicator.

What is better for daily wear – silver or stainless steel?

For those who fear tarnishing and want minimal care, steel is more practical. But it is not a precious metal and does not hold stones as well. Sterling silver 925, with normal care, lasts for decades.

Also read: Why silver tarnishes and what to do about it · How to care for silver, pearls, and gemstones: simple and gentle · How to clean silver jewelry at home: what really works