Michelle Vall was on holiday in Scotland when she found a gold armorial ring which is hundreds of years old.
It's going up for auction next month and is expected to fetch around £10,000.
Michelle, a 53-year-old teaching assistant at Moor Park Primary School, started metal detecting as a hobby just over two years ago, and the ring unearthed on the banks of Loch Lomond isn't her first prized find.
A couple of years ago, the mum-of-two found a very gold hammered coin and that fetched £40,800 at auction.
"I really can't believe my luck," she said. "I took up metal detecting as a hobby because i suffer from anxiety attacks and it really relaxes me.
"I suppose you can go years without finding anything of note but to find something so special again so soon after the fiurst fund is amazing.
"The ring is beautiful and now I am eagerly awaiting to see how much it will fetch at auction."
The ring engraved with a family crest was found at Ducks Bay, on the shores of the Loch and Michelle declared it as Scottish Treasure Trove to the National Museum of Scotland.
But she was then told that the museum did not want to purchase the ring which they said dates from the 16th or 17th century.
Surprised but delighted to have the ring returned to her, Michelle then contacted antiquities specialists Dix Noonan Webb, who handled the sale of the rare coin she found in 2017.
They further researched the ring and discovered that the crest belonged to the Colman family of Brent Eleigh, Suffolk who made their fortune in the mid 16th century from the cloth trade, in the Suffolk town of Lavenham and invested their wealth into land,
Family member Edward Colman is considered to be a Catholic martyr and was beatified by Pope Pius XI in 1929.
Nigel Mills, an antiquities expert at Dix Noonan Webb, said: “The Colman seal ring is an excellent example of a high status ring of the period, of which there are only a very limited number surviving in this condition.
"Metal detectorists like Michelle have contributed vastly to our knowledge by finding treasures that would have otherwise been unknown to exist.”
The ring will be offered in an auction at Dix Noonan Webb's auction rooms in Mayfair, London on Tuesday, September 10.