METEORITES OF NORTH AMERICA. 35 



is repeated; the small bands, which do not seem to be outgrowths of the larger, here also are composed of granular 

 kamacite, but of a finer structure, and consequently appear darker. Schreibersite occurs in tolerably large crystals; 

 in their neighborhood, as well as in the neighborhood of the natural surface, rust is readily developed. 



The principal mass, as above stated, is in the City of Mexico. 



BIBLIOGRAPHY. 



1. 1901: Cohen. Verzeichniss Greifswald Sammlung: Mitth. naturw. Ver. Neu Vorp. u. Rugen, vol. 32, pp. 70-71. 



2. 1904: Ward. Catalogue of the Ward-Coonley Collection: p. 3. 



3. 1905: Cohen: Meteoritenkunde, Heft 3, p. 384. 



ARISPE. 



15 miles N. W. of Arispe, Sonora, Mexico. 

 Here also Moctezuma (Berwerth). 

 Latitude 30° 15' N., longitude 110° 0' W. 

 Iron. Coarsest octahedrite (Ogg) of Brezina. 

 Found 1S98; described 1902. 

 Weight, 18 kgs. (40 lbs.). 



This meteorite is chiefly described by Ward. 1 An abstract of his account foUows: 



It was first discovered in 1898 by some Mexican mescaleros in the mountains some 15 miles northwest of Arispe, 

 Sonora, Mexico. Thinking it to be silver, they hid it; but another party, following up the trail, stole it. After some 

 time and some strife, personal and in the courts, the mass was acquired by Senor Canizaris at Cucurpe, in the Mag- 

 dalena district. This gentleman had a hole drilled in it about half an inch in diameter by 2.5 inches in depth to test 

 it for gold and silver. Finding no trace of either, the mass was laid aside. Its existence was subsequently referred 

 to during a visit to that vicinity of Mr. A. F. Wuensch, a mining expert, who first recognized its meteoric character, 

 and transported it to his home in Denver, Colorado. It is as irregular and shapeless as nearly all masses of meteoric 

 iron, notably those from Mexico and the southwestern portions of the United States, where prolonged decomposition 

 has in most cases corroded and broken down the sharper angles. The area of one side measures 16 by 12 by 9 inches, 

 and shows no pittings, but a few shallow concavities, one of them nearly an inch across, doubtless due to decompo- 

 sition since its fall. The opposite side measures 18 by 13.5 inches, with a thickness of 13 inches. This surface is cov- 

 ered with evenly distributed shallow pittings, ranging from 1.5 to 3 or 4 cm. in diameter, and having sharp .outlines, 

 indicating less decomposition on this surface. 



On one side is a large semilunar depression, nearly 3 inches wide and deep and with nearly vertical walls on two 

 sides and smooth surfaces free from ridges or pittings, indicating that the cavity was due to the decomposition of a 

 great troilite nodule. This empty cavity is the most striking exterior feature of the mass. 



A section surface shows numerous troilite nodules, up to 30 mm. in diameter, with a surrounding envelope of 

 schreibersite, and sometimes containing small patches and angular fragments of nickeliferous iron and even, occa- 

 sionally, masses of chromite 4 to 5 mm. in diameter. Polished or etched surfaces sometimes show arborescent groups 

 of crystals, as large as 10 by 18 mm., of what is apparently cohenite. Numerous large masses of schreibersite are 

 scattered through the iron 30 to 40 mm. in diameter; blades of the same material also occur, 3 mm. in width by 45 mm. 

 in length. The Widmannstatten figures are sharp and clear, showing distinctly the octahedral structure of the iron. 

 The kamacite plates are of unusual width, averaging 3 to 4 mm., and, in one instance, 195 mm. in length. The 

 taenite films are comparatively small, but are noticeable from their difference in color as compared with the adjoining 

 kamacite plates. The iron is further characterized by the almost entire absence of plessite. 



A section across the meteorite shows it to belong to the class of brecciated siderites, and its individual pieces, or sol- 

 dered fragments, are as large as the largest that have ever been recorded. A Y-shaped fissure divides a section into 

 three areas. This fissure varies from a fine line in width to a broken vein of from 1 to 6 mm. in width and filled with 

 troilite. This fracture and its filling with troilite probably occurred while the original mass was still in a state of 

 fusion. The long kamacite plates do not match at the edges of this bifid fissure, but the three areas formed by it 

 show them running in different directions, as if the three pieces had slipped out of their original position and been 

 joined together again by different edges; or it may be that each of these three divisions represents an area of original 

 crystallization. 



Analysis (Whitfield): 



Fe '. 92. 268 



Ni 7. 040 



99. 308 

 Specific gravity, 7.855. 



Mr. J. M. Davison, of the Reynolds laboratory, Rochester, New York, noted the presence 



of a trace of platinum in the Arispe meteorite, also 1.84 per cent of schreibersite. He also 



