The Canadian gold-panning enthusiast found the precious metal, worth around £10,000, earlier this week.
The 20-carat nugget weighs around 18.1grams and was hauled from a river in Dumfriesshire.
The man, who only wishes to be known as “John” from the Gold Rush province of British Columbia, was learning to pan under the watchful eye of expert Leon Kirk.
John said: “Leon was telling me how to look out for haematite, the red-coloured mineral often found with gold.
“We were a few minutes into panning when I found the nugget with a bean tin, an underwater viewing tin with a glass base.
“I saw the piece lying just under the surface of the water and picked it up.”
But he added: “It didn’t look like much and I was just about to throw it back when I thought I should double-check with Leon first.
“I said, ‘Is this gold?’ and I couldn’t understand his excitement.”
It didn’t look like much and I was just about to throw it back when I thought I should double-check with Leon first
“John”
Golden nuggets of this size are extremely rare in Scotland, which does not have any commercial gold mining.
Any Scottish gold extracted or panned is considered to be extremely rare and commands a premium price.
Most of the larger pieces of Scottish gold have been found in this small area of the Lowther Hills which was once known as “God’s treasure house of Scotland”.
Mr Kirk, who runs gold panning courses from the Museum of Lead Mining near Wanlockhead in Dumfriesshire, said: “This is quite exceptional.
“I always knew there were sizable nuggets in these hills but in my decades of panning, have only found very small pieces or flakes.”
