What is a hallmark?

A hallmark is an official series of marks applied to an item of precious metal after it has been independently tested by an assay office.

Its purpose is to confirm that the metal reaches the legal standard of purity represented by the mark. In Britain, hallmarking has been used for centuries and forms an important part of the history of the jewellery trade.

A complete hallmark may identify:

• The precious metal
• The metal’s minimum fineness
• The assay office
• The maker or sponsor
• The year of assay

The principal British hallmark symbols

Traditional British hallmarks are made up of several individual punches. Their order and appearance vary according to the period, metal and assay office.

Metal and fineness marks

The fineness mark expresses how much pure precious metal is present in one thousand parts of the alloy.

Older pieces may carry traditional symbols rather than, or alongside, modern numerical fineness marks. Gold, for example, has historically been identified through crown symbols and carat numerals.

British assay-office marks

The assay-office symbol identifies the city in which the item was tested. Several British assay offices have operated over the centuries, although not all remain active today.

Understanding date letters

Date letters are among the most useful elements of a British hallmark, but they must be interpreted carefully.

The same letter can appear in several different cycles. The correct year is determined by looking at:

• The assay office
• The typeface
• Whether the letter is upper or lower case
• The shape of the surrounding shield
• The style and construction of the jewellery

Date letters are best checked against a reference chart belonging to the correct assay office.

Maker’s marks and sponsor’s marks

What is commonly called a maker’s mark is officially known in modern hallmarking as the sponsor’s mark.

It normally consists of two or more initials contained within a shaped punch. These initials identify the individual or business that registered the mark and submitted the item for assay.

It does not always identify the craftsperson who physically made the piece. A retailer, wholesaler or importing company could register and use its own sponsor’s mark.

Some makers are well documented, while others remain difficult to identify. Initials must therefore be compared with:

• The shape surrounding the letters
• The assay office
• The likely date
• The type of object
• Known registration records

Reading hallmarks on antique jewellery

Antique jewellery rarely presents its information perfectly. Marks may be worn, partially polished away, distorted during resizing or hidden beneath dirt and oxidation.

The hallmark should always be considered as one part of a wider examination. Other useful dating evidence includes:

• Stone-cutting style
• Claw and setting construction
• Hinge and clasp design
• Chain and link construction
• Manufacturing techniques
• Wear patterns and repairs
• Engraving style

A Victorian-style piece carrying a much later hallmark may be a revival design rather than an original Victorian jewel. Conversely, an old piece may have acquired a later replacement component bearing a newer mark.

Why some antique jewellery has no hallmark

The absence of a hallmark does not automatically mean an item is not made from precious metal.

A piece may be unmarked because:

• It was made below the legal hallmarking weight
• It was manufactured outside Britain
• The hallmark was lost through wear or alteration
• A ring was resized through the original marks
• The item predates relevant hallmarking requirements
• It was never submitted for assay
• Only one detachable component was originally marked

Unmarked jewellery should be assessed using appropriate precious-metal testing alongside its construction and provenance.

How to examine a jewellery hallmark

1. Locate the marks. Look inside ring shanks, on brooch pins, near necklace clasps and on the reverse of pendants.
2. Use magnification. A jeweller’s loupe or macro photograph can reveal details invisible to the naked eye.
3. Do not polish the area aggressively. Worn marks can be permanently damaged by excessive cleaning.
4. Identify the fineness mark first. This establishes the stated metal standard.
5. Find the assay-office symbol. The office determines which date-letter chart should be consulted.
6. Compare the complete date-letter design. Match the letter, typeface and shield shape rather than the letter alone.
7. Check the conclusion against the jewellery. The date should make sense alongside the piece’s design and construction.