AMSTERDAM, Netherlands —  A hobbyist with a metal detector struck both gold and silver when he uncovered an important cache of ancient Celtic coins in a cornfield in the southern Dutch city of Maastricht.

"It's exciting, like a little boy's dream," Paul Curfs, 47, said Thursday after the spectacular find was made public.

Archaeologists say the trove of 39 gold and 70 silver coins was minted in the middle of the first century B.C. as the future Roman ruler Julius Caesar led a campaign against Celtic tribes in the area.

Curfs said he was walking with his detector this spring and was about to go home when he suddenly got a strong signal on his earphones and uncovered the first coin.

"It was golden and had a little horse on it — I had no idea what I had found," he said.

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After posting a photo of the coin on a Web forum, he was told it was a rare find. The following day he went back and found another coin.

"It looked totally different — silver, and saucer-shaped," he said. Curfs notified the city of his find, and he and several other hobbyists helped in locating the rest of the coins, in cooperation with archaeologists.

Nico Roymans, the archaeologist who led the academic investigation of the find, believes the gold coins in the cache were minted by a tribe called the Eburones that Caesar claimed to have wiped out in 53 B.C. after they conspired with other groups in an attack that killed 6,000 Roman soldiers.

The Eburones "put up strong resistance to Caesar's journeys of conquest," Roymans said.

The silver coins were made by tribes further to the north — possible evidence of cooperation against Caesar, he said.

Both coin types have triple spirals on the front, a common Celtic symbol.

The two other known caches of Eburones coins have been found in neighboring Belgium and Germany.

Maastricht city spokeswoman Carla Wetzels said the value of the coins is not known — their worth is primarily historical. The Belgian cache of similar size was estimated at around 175,000 euros ($220,000).

The farmer who owned the land agreed to sell his interest to the city for an undisclosed sum.

Curfs, a teacher at a nearby junior college, continues to own the 11 coins he found, but has lent them to the City of Maastricht on a long-term basis. The coins will go on display at the Centre Ceramique museum in Maastricht this weekend.

Curfs said he considers his metal detector habit a meditative hobby and not an obsession.

"I have advice for anybody hoping to get rich like this," Curfs said. "Forget it."