A man kept the rock for years thinking it was gold. It turns out to be much more valuable. Science alert

In 2015, David Hall was excavating in Maryborough Provincial Park near Melbourne, Australia.

Armed with a metal detector, he discovers something unusual – a very heavy red rock resting in some yellow clay.

He took it home and tried everything to open it, and was sure there was a nugget of gold inside the rock – after all, Maryborough is located in the Goldfields, where the Australian Gold Rush reached its peak in the 19th century.

To break down his find, Hall used a rock saw, an angle grinder, a drill, and even doused the object in acid. However, even a heavy hammer couldn’t create a crack. That’s because what he was trying so hard to open wasn’t a solid block of gold.

As he discovered years later, it was a rare meteorite.

“It had this carved, winking appearance,” said Dermot Henry, a geologist at the Melbourne Museum. Tell Sydney Morning Herald In 2019.

“This is formed when they pass through the atmosphere, melt outside, and are sculpted by the atmosphere.”

Hall was unable to open the “rock,” but remained fascinated, taking the nugget to the Melbourne Museum to identify it.

“I’ve looked at a lot of rocks that people think are meteorites,” Henry told Channel 10 News.

In fact, after 37 years of working at the museum and examining thousands of rocks, Henry said only two of the displays turned out to be real meteorites.

This was one of the two.

Maryborough meteorite, with slab cut from the block. (Melbourne Museum)

“If you saw a rock on the ground like this, and you picked it up, it shouldn’t be that heavy,” Melbourne Museum geologist Bill Birch said. Explain to Sydney Morning Herald.

The researchers published a scientific paper describing the 4.6 billion-year-old meteorite, and named it Maryborough after the town near where it was found.

It weighs 17 kilograms (37.5 pounds), and after using a diamond saw to cut a small slice, researchers discovered that its composition contains a high percentage of iron, making it a piece of iron. H5 normal chondrite.

Once you open it, you can also see tiny crystalline droplets of metallic minerals all over it, which are called Chondrols.

“Meteorites provide the cheapest form of space exploration. They transport us back in time, providing clues about the age, composition and chemistry of our solar system (including Earth).” Henry said.

“Some offer a glimpse into the deep interior of our planet. In some meteorites, there is ‘stardust’ older than our solar system, which shows us how stars form and evolve to form the elements of the periodic table.”

“Other rare meteorites contain organic molecules such as amino acids, which are the building blocks of life.”

A slab cut from the Maryborough meteorite. (Birch et al., PRSV, 2019)

Although researchers don’t yet know where the meteorite came from or how long it spent on Earth, they do have some guesses.

Our solar system was a pile of dust and chondrite rocks. Eventually gravity pulled much of this material together to form planets, but the remains mostly ended up in a massive asteroid belt.

Henry told Channel 10 News: “This particular meteorite most likely comes out of the asteroid belt between Mars and Jupiter, and it was pushed out of there due to some asteroids colliding with each other, and then one day it collided with Earth.”

Carbon dating suggests that the meteorite was on Earth between 100 and 1,000 years ago, and there were a number of sightings of the meteorite between 1889 and 1951 that could correspond to its arrival on our planet.

Researchers believe that the Maryborough meteorite is much rarer than gold, which makes it more valuable to science. It is one of only 17 meteorites ever recorded in the Australian state of Victoria, and is the second largest chondrite mass, after a massive 55-kilogram specimen identified in 2003.

“This is only the 17th meteorite found in Victoria, while thousands of gold nuggets have been found,” Henry told Channel 10 News.

“Given the chain of events, it is arguably astronomical that it was discovered at all.”

It’s not even the first meteorite that takes a few years to reach the museum. In a particularly startling story covered by ScienceAlert in 2018, it took a space rock 80 years, two owners, and a stint as a doorstop before it was finally revealed for what it is.

Now is probably as good a time as any to check your backyard for heavy, hard-to-break rocks — you may be sitting on a metaphorical gold mine.

The study was published in Proceedings of the Royal Society of Victoria.

A version of this article was originally published in July 2019.