Israeli teenagers volunteering at an archaeological dig have unearthed hundreds of gold coins that were stashed away in a clay vessel for more than a millennium. The 425 24-carat pure gold coins date back to the 9th-century Abbasid caliphate period and would have been a significant amount of money at the time, said Robert Kool, a coin expert at the Israel Antiquities Authority. “For example, with such a sum a person could buy a luxurious house in one of the best neighbourhoods in Fustat, the enormous wealthy capital of Egypt in those days,” he said. The treasure was discovered last week at an excavation site in central Israel where a new neighbourhood is planned to be built. The excavation director, Liat Nadav-Ziv, said: “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. We can only guess what prevented him from returning to collect this treasure.” It is thought the area housed workshops at the time the treasure was hidden. The identity of the owner is a mystery. “It was amazing,” said Oz Cohen, one of the volunteers who found the treasure. “I dug in the ground and, when I excavated the soil, saw what looked like very thin leaves. When I looked again I saw these were gold coins. It was really exciting to find such a special and ancient treasure.”