A dad in New South Wales pulled off a prank on his son making him believe he'd found a gold nugget while on a mining trip.

Science teacher Jacob Strickling took his two sons, Samuel, 11, and Matthew, 21, on a mining trip to Hill End on June 16.

As Matthew was chipping away at a rock his dad managed to sneak in a 'golden nugget' into the pan which his eldest son later believed was authentic.

Strickling told Newsflare: "In my pocket, I had a large fake gold nugget which was made from some molten lead (quite dense) and sprayed with gold paint.

"As the fake gold nugget was quite large I had to secretly plant it amongst the other rocks, I encouraged Matthew to chip larger pieces.

"I managed to get my youngest son away while I quickly planted the fake gold nugget amongst the pay dirt in the sieve.

"Matthew then used the water and a shaking motion to clean the rocks and get the smaller chunks to pass through the sieve and into the pan.
My absolute favourite moment was at time stamp 2:18 when Matthew notices the gold nugget for the first time. I've watched it 10 times and still laugh!

"Eventually I told him it was a prank. He wasn't happy! It literally took him the rest of the day for him to forgive me!"