Geologists call it a rare and valuable specimen, a relic of billions of years ago that is immensely difficult to study.
Mark Brown calls it the world's original antique, and he'd like to sell you a chunk of it.
Mr. Brown is a mine worker and prospector in Yellowknife, the northern town that lies a 300-kilometre floatplane flight south of the Acasta River Gneiss, an outcrop of rock on a small island that has an utterly unique virtue.
It is, to the best geologists can determine, the oldest known rock on Earth, about 4.06-billion-years-old.
That makes it an exceptional survivor from the time the planet, whose age scientists estimate at 4.55-billion years, was a toddler.
Mr. Brown sees in it a tremendous marketing opportunity, one that has led him to stake a mining claim to the rock, commission a short promotional video and develop a website ready to accept orders - $149.99 for a piece without a display case, $249.99 with one - in seven languages.
He has already removed about 200 kilograms of fallen rock at the site and, if demand is there, is prepared to dynamite the gneiss outcrop itself.
That prospect concerns geologists, who say the rock is a unique window into the world as it once was - and is best studied intact. The study of ancient rock presents one of the few opportunities scientists have to learn about the forces and processes that shaped the Earth billions of years ago, a time when, it's now believed, the first bits of life began to emerge.
"It's a very important location for Canada and for the world and for everyone who is interested in the early Earth," said Robert Creaser, acting chair of the University of Alberta's department of Earth and atmospheric sciences. Older meteorites have been discovered on Earth, as have older mineral grains, but none much bigger than a human hair.
That makes Acasta "quite important from a heritage point of view," Mr. Creaser said.
To anyone but a geologist with sophisticated dating tools, the rock itself is indistinguishable from that in the vast regions of the Canadian Shield.
But the sheer age of the rock is, Mr. Brown said, "a mind-blower" that imparts a metaphysical experience of permanence. He calls it the Rock of Ages, a deliberately religious metaphor for an object whose natural setting carries a mystique so great, he said, that "I can establish my own church there."
Not only that, he believes the rock has all manner of money-making potential. People have talked about using it for headstones or chess pieces. Bits of the gneiss have gone to the Royal Ontario Museum, the Smithsonian in Washington, D.C., and to universities, collectors and researchers from Denmark to Japan. Mr. Brown has even heard from a man so eager for an authentic encounter that he is determined to fly to the site - air charters cost about $4,500 - and collect a piece for himself.
"It's just raw, 100 per cent what-can-you-do-with-it? sort of material," Mr. Brown said.
Canada preserves archaeological sites but not - unless they are in a park - sites of geologic importance. Australia, by contrast, creates "geological monuments" to highlight particularly unique places.
Efforts to formally protect the Acasta gneiss started decades ago, but never gained traction due to lack of interest. But even the first person to claim the site believes the government should have stepped in to halt any future claims after his expired this year.
"I don't know why they haven't protected it," said Walt Humphries, another Yellowknife prospector who sold enough of the gneiss to fill a refrigerator.
Geologists say the Acasta River site is largely protected by its isolated location - and by the fact that old rock seems to have limited market value. And the man who first dated the rock is also skeptical of the sales pitch. Even at the Acasta River site, the oldest rocks are mixed with younger ones - and verifying an individual chunk would cost thousands of dollars.
"It's a bit dishonest to sell it without dating every single piece of rock," said Sam Bowring, a professor of geology at the Massachusetts Institute of Technology. "And that would be an extremely expensive endeavour."
All of which means Mr. Brown's ability to profit will depend largely on his skills as a salesman, which have so far produced little fruit. At the Vancouver Olympics, he demonstrated the rock at the Northern House exhibition area, but managed to sell only a half-dozen. He blames poor sales on the fact that he was barred from soliciting.
Mr. Brown has a Grade 11 education, lives in a 7.5-square-metre shack without electricity or running water, charges his cellphone using parking lot block-heater plug-ins and boasts that, if need be, he will trap squirrels for breakfast. He is, he said, a bush man capable of great self-sufficiency, which has already allowed him to invest $15,000 of his own money into the Rock of Ages project. And this is just the start. He plans to discuss a marketing strategy with a communications firm Monday.
The rock "is the oldest known thing on the planet," he said. "It doesn't get any better."