The ultra-rare sword, which doesn't resemble most ancient weapons in the world, was made around the year 3000BC and came from eastern Turkey.
However, the sword was contained in a cabinet as part of a medieval collection.
It was only when a local PhD student and expert in ancient weaponry noticed the sword that it was removed for further analysis to pinpoint its date.
The sword could have been a ceremonial object or an offensive weapon that was used in combat.
Another hypothesis is that it was part of a burial and was casually retrieved by townsfolk before ending up in a museum.
Vittoria Dall'Armellina at Università Ca' Foscari in Venice saw the sword in a small cabinet surrounded by medieval items at the Mekhitarist Monastery on the Saint Lazarus Island in the Venetian Lagoon.
Mekhitarist Monastery, which is the headquarters of the Armenian Catholic Mekhitarist Congregation, includes museums, a church, residential quarters, a library, museums, picture gallery, printing plant and research facilities.
The weapon caught the eye of Dall'Armellina, whose master's degree and PhD included a study on the origin and evolution of swords in the Ancient Near East.