A Crusades-era hand grenade that was retrieved from the sea off the Israeli coast several years ago has been handed over to the Israel Antiquities Authority (IAA) by a family that inherited it.

Made from heavy clay and gorgeously embossed, the incendiary weapon would have been used like some sort of a molotov cocktail. It was filled with naphtha -- a flammable sticky liquid known as Greek fire -- then sealed and hurled onto enemies.

The deadly device was rather popular in naval battles as the fire could easily destroy ships.

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According to the IAA, the grenade was common in Israel during the Crusades between the 11th to 13th century and until the Mamluk era, which ran from the 13th to the 16th century.

The weapon was recovered by the late Marcel Mazliah, a worker at the Hadera power plant in northern Israel. It wasn't however the only item that belonged to Mazliah's varied collection.

The archaeologists were surprised to find a treasure trove of metal artifacts, the earliest of which are 3,500 years old.

Mazliah's family explained the man retrieved such items from the sea over a period of years while working at the power plant.

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His other finds include a toggle pin and the head of a knife from the Middle Bronze Age, which date back more than 3,500 years. He also recovered candlestick fragments, two mortars and two pestles dating to the 11th century.

"The items were apparently manufactured in Syria and were brought to Israel," Ayala Lester, a curator with the Israel Antiquities Authority, said in a statement.

The archaeologists believe the metal objects, most of which are decorated, fell overboard from a metal merchant's ship in the Early Islamic period (638- 1099)

"The finds are evidence of the metal trade that was conducted during this period," Lester said.

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