Katsuyuki Mitsumura shows how he found what turned out to be a meteorite in his backyard while Shinichi Kawakami of Gifu Shotoku Gakuen University explains what led to the conclusion that the stone was actually a meteorite. (Video footage by Ken Murota)

GIFU--Katsuyuki Mitsumura was working in his garden in October 2012 when he came across a shiny fragment.

He took the piece into his house because it looked pretty.

Mitsumura, 74, put the "rock" on display in his home but never gave it much thought until June 2017 when he read a newspaper article about a meteorite that included a photo.

"I wonder if my piece is also a meteorite," Mitsumura thought at the time.

On March 1, a news conference was held here to announce that his finding had been certified as a meteorite.

Mitsumura's discovery is the first official recognition of a meteorite in Japan in 14 years. The last certified meteorite was the Kamioka meteorite found in Akita Prefecture.

"I never had a special interest in rocks, but I just happened to take it back into the house with me," Mitsumura said. "I have been working in that garden for 30 years but I have no idea how long the meteorite was there."

Mitsumura first took his specimen to the Gifu Prefectural Museum in Seki and officials there introduced Mitsumura to Shinichi Kawakami, a professor of earth and planetary science at Gifu Shotoku Gakuen University.

Further analysis was conducted by a team of scientists from various organizations such as the University of Tokyo, the National Institute of Polar Research, the Tokyo Metropolitan University and the Graduate University for Advanced Studies.

The team concluded that Mitsumura's finding was an iron meteorite. It weighs 6.5 kilograms and has dimensions of 15 centimeters by 20 cm by 15 cm.

Kawakami said the specimen would be valuable in unraveling the process behind the formation of the solar system.

On Feb. 12, the Meteoritical Society, an international organization for meteoritics and planetary science, officially recognized the finding and named it the Nagara meteorite for the neighborhood where it was found.

The meteorite will be on display at Gifu science museum until June 30.