Roman Metal Armour-Polished or Dull?

[Urselius]

Historiae Romanae, Cassius Dio:

"After this event Nero took him up to Rome and set the diadem upon his head....The centre was occupied by the civilians, arranged according to rank, clad in white and carrying laurel branches; everywhere else were the soldiers, arrayed in shining armour, their weapons and standards flashing like the lightning."

I think the level of spit and polish would have varied greatly due to circumstances. The armour of legionary after two weeks marching in German bogs and forests would not have been very shiny at all. The same soldier reviewed by a dignitary might have managed to bring his armour to a high degree of polish. In addition to laquer and paint a thin application of olive oil would preserve the shine on metal for some time.