Youths volunteering at an archaeological dig in central Israel have found 425 gold coins that had lain buried in a clay jar for 1,100 years.

Most of the money dates back to the early Islamic period, when the region was part of the Abbasid caliphate.

The coins weigh 845g (30oz) and would have been worth a huge sum when they were buried – enough to buy a luxurious home in one of the caliphate’s cities.

Who owned the cache, and why they never returned to collect it, is a mystery.

“The person who buried this treasure 1,100 years ago must have expected to retrieve it, and even secured the vessel with a nail so that it would not move,” the directors of the excavation, Liat Nadav-Ziv and Elie Haddad of the Israel Antiquities Authority, said in a statement.