Silver Plated vs Solid Silver: The Acid Test Explained

Solid silver, or sterling silver, is an alloy containing 92.5% pure silver, often identified by a “925” mark or a lion passant hallmark. Silver plate consists of a thin layer of pure silver electroplated over a base metal like copper or brass, typically bearing marks like “EPNS” or “A1.” The acid test uses a nitric acid solution applied to a deep scratch; a bright red color confirms solid silver, while green or brown indicates base metals and silver plate.

Imagine you are at a dusty estate sale in rural Pennsylvania, eyeing a heavily tarnished tea service. The seller claims it is solid silver, but the price seems suspiciously low. The piece lacks clear documentation of provenance, and you need to know for sure before making a costly mistake.

How can I tell if my silver is real sterling or just plated?

The first step in authentication is always visual inspection. Before resorting to chemical testing, examine the piece closely with a jeweler’s loupe.

You are looking for specific markings stamped into the metal. American sterling silver produced after 1850 will almost always be stamped with the word “STERLING” or the number “925”.

Older American pieces might be coin silver, which is 90% pure and usually marked “COIN” or “STANDARD”.

Conversely, silver plate will feature different stamps. Look for “EPNS” (Electroplated Nickel Silver), “EPBM” (Electroplated Britannia Metal), or quality indicators like “A1” or “Quadruple Plate”.

If a piece has no marks at all, it is highly likely to be plated.

Identifying these marks manually can take hours. Using the Antique Identifier app, you can simply take a photo and get an instant result.

What are the common hallmarks and assay marks to look for?

In the British system, hallmarks are heavily regulated. A genuine English sterling piece will feature an assay mark indicating the city of origin, a date letter, a maker’s mark, and a lion passant.

These stamps guarantee the silver’s purity. Without them, you cannot establish a reliable attribution.

When preparing a condition report or determining an auction estimate, an appraiser relies heavily on these marks.

Silver plate makers often created pseudo-hallmarks to confuse buyers. These fake marks might look like shields or crowns but do not correspond to any official assay office.

This technique of reading marks is similar to what we cover in our guide on Sterling Silver vs. Silver Plate: The “Ice Cube” Test and More.

How does the acid test actually work on antique silver?

When visual inspection fails, professionals turn to the acid test. This is a destructive test, so it should only be performed in an inconspicuous area.

You must make a small, deep notch in the metal—often using a jeweler’s file—to penetrate any potential plating.

Apply a drop of testing solution (a mixture of nitric acid and potassium dichromate) to the notch.

If the liquid turns bright red, the item is solid sterling silver. If it bubbles and turns green, you have hit a copper or brass base metal, proving it is merely silver plate.

Understanding this distinction is critical for establishing fair market value and replacement value. A solid silver tray might be worth thousands in the collector market, while a plated version is worth only a fraction of that amount.

What are the red flags for silver forgery and fake marks?

Forgery detection is a major part of any professional appraisal. Unscrupulous dealers sometimes solder genuine hallmarks onto modern base metal bodies.

Look for mismatched patina, visible solder lines around the marks, or stamps that appear soft and cast rather than crisp and struck.

Another red flag is “bleeding.” If you see a yellowish or reddish tint showing through the silver on high-wear areas (like the handle or base), the base metal is exposed.

In such cases, restoration or conservation might not be worth the investment, as the underlying value simply isn’t there.

Always consult a reputable antique dealer or auction house if you are uncertain about a piece’s authenticity.

Related Antique Identification Guides

Expand your expertise with these related guides: Antique Teapot Identification: Finding English Silver and Ceramic Marks, Sterling Silver vs. Silver Plate: The “Ice Cube” Test and More, Decoding British Silver Hallmarks: How to Read the Lion and Anchor