File1293724667.jpg-(66 KB, 150x500, spear of fuchai.jpg)
the sword of Goujian, king of Yue was bronze, and therefore, did not rust.
furthermore, the scabbard for it was airtight, and the water created an anerobic without oxygen, preventing significant oxidation. net result was, when the sword was discovered, it was literally as fresh as the day it was placed in the tomb 2000 years earlier.
and this is the Spear of Fuchai, Goujian's equally fearsome rival in war, king of Wu.