208 MEMOIRS NATIONAL ACADEMY OF SCIENCES, VOL. XIII. 



FRANCEVILLE. 



El Paso County, Colorado. 



Latitude 38 48' N., longitude 104 35' W. 



Iron. Medium octahedrite (Om) of Brezina. 



Found 1890; described 1902. ^ 



Weight, 18.3 kgs. (41.33 Ibs.). 



This meteorite was described by Preston. 1 The following is an abstract of his account: 



This iron was found by Mr. David Anderson, about 1890, on Government land in El Paso County, Colorado, 1.5 

 miles southwest of the home ranch of Skinner and Ashley, which is east of Franceville. In Mr. Anderson's own 

 words, "It was totally above ground, and I found no signs of any other. When I found the meteorite, I simply 

 pushed it with my foot, but I found I could not move it. The following day I went back with a wagon and got it to 

 the ranch. I do not think at the time the land was entered by anyone; it was not near to any road." 



The meteorite, from the time at which it was found until purchased by Professor Cragin, of Colorado College, was 

 kept in the home of Mrs. Anderson, in Colorado Springs, half forgotten, and when Professor Cragin called to see it, 

 was finally found beneath an old lounge. 



The weight of the iron is 41 pounds 6.5 ounces, or 18.3 kg. 



In form it is a decidedly flattened rhombic pyramid, with a somewhat sharp ridge extending around the center 

 of the mass on the four rhombic sides. The dimensions of the mass in these directions are 21 by 23 cm. On one side 

 of this central axis the pyramid projects 6 cm., on the opposite side 5.5 cm. 



Two small corners of the mass have been broken off and have the appearance of very old breaks, as the surfaces 

 are entirely oxidized. These surfaces show a markedly octahedral cleavage. 



The decidedly octahedral form of this iron seems unquestionably due to its separation along natural cleavage 

 planes from a much larger mass. But it is surprising that the form should not have been much more distorted by the 

 erosion due to friction in passing through the atmosphere. 



The whole iron is more or less mottled, ranging in color from a reddish brown to a brownish black, and is entirely 

 covered with pittings on all sides. Those on the upper side are much more distinct, owing to their size and depth, 

 than elsewhere. 



Upon slicing the mass, but one troilite nodule of any size was found. This occurred on one end piece and the 

 adjoining slice, and was 14 mm. in diameter, with two small patches of nickeliferous iron in its center. 



The slices show more or less of fractures extending across their surfaces along the natural cleavage faces, the edges 

 of the kamacite plates, and in some instances the rhombic forms produced by the Widmannstatten figures are strongly 

 outlined by these fissures. The figures are readily brought out by etching and are particularly sharp and clear and of 

 large size. 



The kamacite plates average from 1 to 1.5 mm. in diameter, with an occasional one of 2 mm. They are unusual, 

 from the fact that they extend in an unbroken line in many instances from 90 to 120 mm. in length. The taenite 

 occurs in minute films between the kamacite plates. 



The plessite patches are comparatively small for an iron of such coarse crystallization. Some of these patches 

 show no structure when etched, except a slightly pitted surface, while others are prominently made up of alternate 

 layers of kamacite and tsenite, producing the sharply defined Laphamite lines. 



Schreibersite is not visible on the etched surfaces megascopically, nor even surrounding the troilite nodules, as 

 is usually the case. 



Analysis by J. M. Davison: 



Kamacite and tsenite 99. 1601 . 



Combined carbon, not determined. J So 



Schreibersite 0. 8371 



Graphite and silicates (trace) 0. 003 [insoluble in HC1. 



Platinum (from 23.9 grams) trace] 



100. 

 Composition of kamacite and tsenite: 



Fe 91. 92 



Ni 8.13 



100. 

 The meteorite is distributed. 



BIBLIOGRAPHY. 



1. 1902: PRESTON. Franceville meteorite. Proc. Rochester Acad. Sci., vol. 4, pp. 75-78. (With cuts showing 

 exterior appearance of iron and etching figures.) 



