Pennyweight.

What does the swan hallmark mean?

Short answer

Swan: silver of at least 800, of foreign or uncertain origin, marked in France.

A mark is a statement, not proof: it can be forged or struck on a plated piece. An assay confirms it (touchstone and acids, or X-ray fluorescence).

The stamp in detail

ItemWhat the tables say
Stampswan
ClassHallmark symbol
Silver fineness800 parts per thousand (80 % silver)
Legal standard (silver 800)United Kingdom, Vienna Convention states, France
Source checkChecked against the sources listed below
Date clueNot before 1893. The swan has been used since 1893.

What swan can be mistaken for

Pieces that look like silver and are not:

What a stamp cannot settle: Silver, white gold or platinum without marks: white colour does not tell them apart.

What settles it:

Related stamps

Other ways the same fineness is stamped: 800.

Also in this group: lion passant, Britannia, leopard head, anchor, rose, castle, crown, orb.

All stamps and the search · UK hallmarks and date letters

Frequently asked

What does swan mean on jewelry?

Swan: silver of at least 800, of foreign or uncertain origin, marked in France.

Is the swan mark proof of the metal?

A mark is a statement, not proof: it can be forged or struck on a plated piece. An assay confirms it (touchstone and acids, or X-ray fluorescence).

Sources

All sources are listed with the method on the sources page.