Matt Betteridge was on an evening walk when his eye caught a "glimmer sticking out of the dirt".
Key points:
Matt Betteridge found an 834-carat sapphire while specking in the central Queensland Gemfields
Gem hunters often look for stones after rain because it washes away some of the topsoil
The Gemmological Association of Australia said keeping the stone in one piece could make it more valuable
He quickly learnt it was not a random rock but a sparkling sapphire the size of a "small child's fist".
"The rain unearthed it that little bit … I thought it was going to be an average-sized stone until I couldn't pull it out," Mr Betteridge said.
"It seemed very heavy, popped out a nice ball, like a small child's fist, but very heavy like a lump of lead."
Mr Betteridge found the stone about 100 metres from the mining claim he lives on at the Reward fossicking land near Rubyvale in Queensland's Gemfields.
The region is one of the largest sapphire-bearing areas in the world.
Mr Betteridge found it late last month while out specking, the practice of walking around scanning the ground for stones.
After getting it valued, he realised it was an 834-carat sapphire, which he described as "very, very rare".
Footage of Mr Betteridge finding the sapphire, and repeating the term "holy dooley" in surprise, had by Saturday amassed more than 260,000 views on TikTok .
Rain unearths gems
Gem hunters believe they have a better chance specking after rain because it washes away some topsoil.
The Central Highlands and Coalfields region has been inundated in recent days, with widespread rain and flash flooding hitting some communities.
The Bureau of Meteorology (BOM) said it recorded 194 millimetres of rain in Sapphire from October 16 to October 21.
Rubyvale recorded 182mm during the same period.
BOM said Rubyvale and Sapphire broke 13-year records for the amount of rainfall they received in the 24 hours to 9am on Wednesday.
Mr Betteridge said that, while Reward was only accessible by 4WD, people were still out searching for sapphires after the rain.
"All the speckers are out covering ground, even in-between the showers," he said.
Stone to be retained
Mr Betteridge sent the stone to a local gem cutter for an approximate valuation.
It is estimated to be worth $12,500.
While it contained some crystal that could be cut into jewellery, Mr Betteridge was keeping the stone in one piece to display its full size.
The Gemmological Association of Australia's Helen Levonis, a jewellery valuer, said collectors often avoided cutting into large stones to produce smaller sapphires.
She said receiving anything more than a five-carat gemstone, "which is only a gram", was very rare in sapphires.
"When you get something … like an 830-carat sapphire, that's phenomenal," Ms Levonis said.
She said it would be a "shame" to cut it up.
"It could have far more value as the crystal than it will as cut-up pieces of sapphire," Ms Levonis said.
Ms Levonis said people were increasingly interested in conserving specimens like Mr Betteridge's stone.
"These sapphires grew hundreds of thousands of years ago," she said.
"There are no more coming … and we need to respect that when you see something that's 800 carat."
'Try your luck'
Mr Betteridge said the stone would be kept as a family heirloom and would be displayed during the region's annual Festival of Gems.
He also encouraged others interested in gem-hunting to visit the Gemfields.
"It was found on general fossicking grounds … everyone can have a go," Mr Betteridge said.
"Grab a fossicking ticket and camping permit and try your luck."