What the assay card on a minted bar tells you

This page explains how to read one. For the general framing of these guides, see the educational disclaimer.

The short definition

An assay card is packaging. It is a printed card, usually with a clear sealed window, that holds a bar and lists the maker's claims about it.

The word "assay" means testing metal for its content. On the card, it is mostly a name for the package. The card is the maker's statement. It is not a lab report written for your bar.

What is usually printed on the card

Layouts differ from maker to maker. Many cards show some or all of these:

• Maker. The refiner or mint that made the bar.
• Metal. Silver, written out.
• Weight. For example "1 oz" or "10 oz." On bullion, that means troy ounces of fine silver unless the seller clearly says otherwise. See What a troy ounce means.
• Fineness. For example ".999," meaning 999 parts silver per 1,000. See Silver purity, hallmarks and fakes.
• Serial number. A number that should match the one stamped on the bar.
• Other print. Some cards add a signature line, a statement that the bar meets the stated weight and fineness, or a security feature such as a hologram.

The same weight, fineness and serial lines are usually stamped on the bar itself. The card repeats them.

Labeled example

Example (made-up card, not a real product):

Example Refinery · Fine Silver · 1 oz · .999 · Serial EX000123

Read it line by line:

• "Example Refinery" is who stands behind the claim.
• "1 oz" and ".999" are the numbers that feed melt math: weight times fineness.
• "EX000123" should match the serial stamped on the bar through the window.

Nothing on that card tells you what the bar is worth today. For that framing, see What melt value means and What spot price means.

What the serial number is for

Look through the window and compare the number on the bar with the number printed on the card. If they match, the card and the bar are consistent with each other.

That is a consistency check. It tells you the bar and its package go together. It does not test the metal.

If the numbers do not match, or the seal looks opened and resealed, treat that as a reason to ask questions before relying on the card.

What the card does not prove

• It is not a lab test of your bar. The card states the maker's claims. A matching serial is a consistency check, not a laboratory assay.
• It does not add silver. The card is packaging. The metal is the bar. A carded 1 oz bar and a loose 1 oz bar of the same fineness hold the same silver.
• It does not set a price. Packaging can help a bar look tidy on a resale table. Weight and fineness are what feed melt math.
• It is not impossible to copy. Printed cards can be imitated like any other packaging. The basic checks in Silver purity, hallmarks and fakes still apply.

Card, bar and invoice together

The card is one of three places the same facts should line up:

1. The bar: stamped maker, weight, fineness and serial.
2. The card: printed maker, weight, fineness and serial.
3. The invoice: product description, weight and quantity. See How to read a dealer invoice.

When all three agree, the paperwork is consistent. When one disagrees, that is the line to ask about.

For how carded minted bars compare with cast bars, see Cast bar vs minted bar.

FAQ

Does an assay card prove the bar is real?

No. The card is packaging. A matching serial is a consistency check, not a lab assay.

Does "assay" mean someone tested my bar?

Not on its own. On the card, "assay" is mostly the name of the package. The printed lines are the maker's claims.

What should match between the card and the bar?

The maker, weight, fineness and serial number, where both show them.

Do cast bars come in assay cards?

Some do. Cast bars are more often sold loose or in a simple sleeve. See Cast bar vs minted bar.

Does the card change how much silver is in the bar?

No. The silver is in the bar. Weight times fineness is the same carded or loose.