A- NEWLY FOUND iMETEOKIC IRON FHOM PERRYVILLE, 

 PEERY COUNTY, MISSOURI.^ 



By George P. Meerill, 

 Head Curator of Geology, United States National Museum. 



The iron described below was found by Mr. John Monaghan in 

 August, 1906, on the farm, of a Mr. Patrick Monaghan, about 1 mile 

 west of the town of Perryville It lay in an open field and was about 

 three-fourths buried in the soil. Nothing is known regarding its fall. 

 As secured by the United States National Museum, the mass weighed 

 17.386 kilograms, including a 75-gram fragment that had been cut 

 from it for testing. Allowing for waste in cutting, 17.5 kilograms 

 would probably represent its original weight as nearly as obtainable. 

 How much had been lost by oxidation from the exterior surface it is, 

 of course, impossible to state. 



The general appearance of the mass is well shown in figures 1 and 

 2, plate 44. The surface was almost completely coated with oxidation 

 products, and scales of oxide could be readily removed by means of 

 any hard, sharp instrument. Nevertheless, indications of surface 

 fusion m its flight, in the shape of obscure, shallow pittings, were still 

 evident, and are showTi in the plate. In figure 2 two considerable 

 pits, formed through the oxidation of troilite nodules, are in evidence. 

 An etched surface of the iron brings out some rather unusual features. 

 In structure the iron is an octahedrite, but the crystallization is so 

 fine as to be almost microscopic. (See pi. 45.) The metallic plates 

 aligned parallel with the octahedral face are rarely, if ever, a millimeter 

 in thickness, and are lacking in uniformity throughout their lengths,! 

 They are also wavy, forming an irregular network of lines with a 

 general octahedral trend as shown in figure 2 of plate 45. Parallel 

 with these plates lie the extremely thin, almost microscopic plates of 

 schreibersite, recognizable by the naked eye only by their bright 

 metallic luster, and not at all dift'erentiated in the photographic repro- 

 duction. The structure, on the whole, and particularly with refer- 

 ence to the uneven crystallization, as shown on an etched surface, 

 more nearly resembles the iron of Ballinoo, West Austraha,^ than 



1 Catalogue No. 428, U. S. National Museum. 



2 Described by H. A. Ward, Ainer. Journ. Sci., vol. 5, 1S98, p. 136, and classified as a "Finest octahe- 

 drite. Off." 



Proceedings U. S. National Museum, Vol. 43— No. 1943. 



595 



