Some 350 pieces of rare marble were found buried under a floor dating back to the Crusaders in the ancient Israeli port city of Acre, archaeologists said.

In excavations conducted by the Israel Antiquities Authority north of the city's old city walls at a site where a new school building is to be constructed, archaeologists found the marble hoard hidden beneath the cellar floor of an ancient collapsed building, the authority said in a statement Wednesday.

Edna Stern, head of excavations at the site, said among the items found were two marble tombstones with Latin inscriptions, flat marble slabs of extraordinary quality, a large stone cross and a large fragment of porphyry, which she said is a rare precious purple stone which was the color of Royalty in Roman times.

"Crusader Acre was an important center for international trade and the marble hoard reflects the magnificent buildings erected here that have not survived," Stern was quoted saying.

Stern said experts said the owner of the marble hoard may have been a merchant or collected it for construction but feared for his life and decided to bury the valuable stones until tensions abated.