Copyright - M.Bandli - Historic Meteorites

The cut and etched face of Shirahagi reveal the iron's traumatic past. Photo credit:  Murayama (1953).

CATALOG No. B242.2

PROVENANCE: Institute of Meteoritics (IOM), University of New Mexico; The Jay Piatek Collection.

REMARKS: 

Every now-and-then I read about a meteorite whose cultural fascination exceeds its scientific importance. Naturally, these superstars are assigned to my wish-list. But even rarer than that is the occasional meteorite that shares both aspects in an unprecedented and equal fashion. Come Shirahagi - a peculiar and twisted iron, whose journey, from riverbed to royalty, earns it a spot in the meteorite hall-of-fame.

The Shirahagi iron was discovered in April of 1890 near a waterfall on the Kamiichi-gawa River, Japan. A prospector named Sadajiro Nakamura found the 22.7kg iron in the gravel and gave it to his employer, Issei Kobayashi. The iron was likely transported to that spot via snowmelt from Saotome-Dake Mountain and eventually stranded on a gravel bar on the river.

Five years later the iron was recognized as a meteorite by Kwaijiro Kondo of the Geological Survey of Japan. Shortly thereafter a well-known politician and Foreign Affairs Minister named Takeaki Enomoto caught wind of the celestial iron and purchased the meteorite. Enomoto was so fascinated by the "iron from the stars" that he commissioned swordsmith Kunimune Okayoshi to cut about one-fifth of the meteorite off to be made into swords called "The Meteor Swords." By 1898, a total of three swords were produced and, although the process was exceptionally difficult, the steel from the meteorite had a beautiful finish with patterns that resembled "knots in wood."

The longest sword was presented to Crown Prince Yoshihito, who would become the 123rd Emperor of Japan, and the remaining two swords were kept in the Enomoto estate. The first Meteor Sword is shown here at the Toyama Science Museum:

http://www.tsm.toyama.toyama.jp/curators/aroom/hokusin/img/katana.jpg

It wasn't until the middle of the 20th century that the true scientific fascination of this unusual meteorite would be appreciated, after Sadao Murayama of The Tokyo Science Museum noticed something peculiar on a portion of the etched surface.

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SHIRAHAGI  
Chubu, Japan
Found in April, 1890
Iron, IVA

What apparently began as a flat, discus-shaped body had been completely bent in the shape of a "U". Further etching revealed remarkable displacements of kamacite and lamellae along with a general state of unprecedented deformation. In his work, Murayama attempts to explain the cause of such tremendous forces, ruling out artificial bending and concluding that the meteorite was most likely deformed through great forces during its atmospheric passage.

Shirahagi is also one of the few meteorites to have a respective monument made in its honor. The shrine to the meteorite is located in Toyama, Japan, and can be seen here:

http://www.tsm.toyama.toyama.jp/curators/aroom/hokusin/img/sirahi.jpg

To this day it remains one of the most remarkable irons ever found. Coupled with its rich cultural history, Shirahagi is truly an historic meteorite!


References:

Miura, Y., Yanai, K., & Lancu, O. G. (1994) Japanese Found Meteorites Similar to Anatarctic Meteorite Collection. Abstract of the 25th Lunar and Planetary Science Conference, held in Houston, Tx, 14-18 March, 1994., p. 918.

Murayama, S. (1953) The Peculiar Structure of the Shirahagi, Japan, Siderite. Meteoritics and Planetary Science, Vol. 1, p. 99-102.

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