On: Archaeologists find 3000-year-old sword, exception...

[masklinn]

Fwiw bronze does oxidise quite readily, but the copper oxide is not porous, and becomes a resilient copper carbonate.

Which is why bronze and other copper-alloy artefacts are extremely resilient, unless they come in contact with chlorides and get bronze disease.

[Paul-Craft → masklinn]

I can tell you have some experience with old bronze/copper. Most people do not even know what "bronze disease" is.

[brohee → Paul-Craft]

A lot of people learned about it when tutorials on inducing it on statues of questionable personnalities sprouted up.