On the German island of rügen the Amateur archaeologist in the company of his 13-year-old assistant to the investigated area, when one of them noticed something shiny in the ground that was initially mistaken for debris from the foil.
Because they stayed silent concerning their original sighting, the full treasure trove was retrieved.
"It was the find of my life", said Schön, who had to keep his discovery under wraps until now.
More than 100 of the coins have Christian crosses on them and are believed to have been minted in the kingdom of Bluetooth.
A coin unearthed at the dig. Pictured, ancient coins from the era of the Byzantine Empire (Seventh century), which were found last summer during excavations near the Arab Israeli village of Abu Ghosh near Jerusalem, during a press tour of the national treasures storerooms of the Israel Antiquities Authority in Beit Shemesh on March 19, 2017. The oldest coin, a Damascus dirham, dates to 714 CE, and the newest is a penny from 983 CE.
At that time Harald was at war with his son, Sweyn Forkbeard, so it is surmised that the hoard was buried by the king in his flight.
His nickname - from one dead tooth that looked bluish - is now best known for the wireless Bluetooth technology invented by Swedish telecom company Ericsson.
"We have here a rare case, when a discovery seems to be related to historical sources", says the chief archaeologist of Mecklenburg-Vorpommern, Detlef Jantzen.
The technology, developed to wirelessly link computers with cellular devices, was named after Bluetooth because of his knack for unification. This is because of his impeccable communication skills which helped him unite modern-day Norway, Germany, Sweden and Denmark. The symbol of Bluetooth is also a mixture of two letters of runic alphabets representing the initials of King Harald.