Page "Brass" Paragraph 60

Brass made during the early Roman period seems to have varied between 20 % to 28 % wt zinc.

The high content of zinc in coinage and brass objects declined after the first century AD and it has been suggested that this reflects zinc loss during recycling and thus an interruption in the production of new brass.

However it is now thought this was probably a deliberate change in composition and overall the use of brass increases over this period making up around 40 % of all copper alloys used in the Roman world by the 4th century AD.