Mineralogists at the Royal Ontario Museum had their first look Wednesday inside a rare, 53-kilogram meteorite chunk found near Springwater, Sask., in 2009.

After 48 hours of careful cutting, a wire saw studded with diamonds released a piece of rock about the size of a large slice of bread Wednesday morning from a hunk as large as a high school student's backpack.

Kimberly Tait, the museum's associate curator of mineralogy, pried the piece away from the main chunk — a grey rock covered in slightly rusty, brown patches — to reveal interconnected, translucent greenish spots of a silicate mineral called olivine mottled through a grey iron-nickel alloy.

"It's like Christmas," she later said of her first glimpse inside the precious rock purchased by the museum in recent weeks.

Tait hopes the rare, 4.5-billion-year-old meteorite will help researchers learn more about the early universe, the formation of the minerals inside asteroids, and about the similar minerals deep inside the Earth, at the boundary between its iron core and its outer mantle.

Ian Nicklin, an earth sciences technician at the museum, likened meteorites to "little time capsules."

"They show us features and textures of things that we don't see anywhere else anymore," he said. "So they're fundamental to our understanding of how the solar system did form."

The Springwater meteorite is a rare kind known as a pallasite, from deep inside a large, planet-like asteroid with an iron core. Of the 35,000 meteorites found on Earth, only 84 have been pallasites, and only three of them have been found in Canada.

Pieces found in 1931

Three smaller pieces of the ROM's meteorite were originally found in a farmer's field near Springwater, Sask., in 1931. It is believed to have originated from the asteroid belt between Jupiter and Mars.

The 52.8-kilogram chunk — the biggest piece of a pallasite ever found in Canada — was recovered by a meteorite hunter who combed through the site again with an ATV and modern metal detectors in 2009.

"Having something that large survive through the atmosphere is very rare," Tait said.

The slice will eventually be put on display in the museum's Vale Inco Limited Gallery of Minerals.

Another slice is being cut for research purposes.

The 1931 pieces of the Springwater meteorite were mostly cut into small pieces and distributed to museums around the world, Tait said. The new slices will allow for larger-scale studies impossible with those earlier pieces, such as determining the size and spacing of individual grains.

One thing that's special about the meteorite is the fact that the olivine and iron are found together, something that never occurs on Earth, Tait said. "It's an odd juxtaposition."

The museum bought the meteorite chunk with money from its Louise Hawley Stone Fund and from the Ontario Ministry of Heritage.

Tait said the museum has a policy of not disclosing how much it pays to acquire artifacts, but acknowledged the price tag was "more than I make in a year."