Page "Brass" Paragraph 54

The compositions of these early " brass " objects are very variable and most have zinc contents of between 5 % and 15 % wt which is lower than in brass produced by cementation.

These may be " natural alloys " manufactured by smelting zinc rich copper ores in reducing conditions.

Many have similar tin contents to contemporary bronze artefacts and it is possible that some copper-zinc alloys were accidental and perhaps not even distinguished from copper.

However the large number of copper-zinc alloys now known suggests that at least some were deliberately manufactured and many have zinc contents of more than 12 % wt which would have resulted in a distinctive golden color.