NO. 5 HEXAHEDRITES — HENDERSON 5 



Table 1. — Continued 



28. Keen Mt., Va 6.7 1950 



29. Kendall County, Tex 21 1887 



30. La Primitiva, Chile 3.1,4,1.5, 1888 



4.3, 9 



31. Lick Creek, N. C 1.24 1879 



32. Locust Grove, Ga 10 1857 



33. Lombard, Mont unknown ? 



34. Mayodan, N. C 16 1950 



35. Mejillones, Chile — * 1875 



Mejillones, Chile 14.5 1905 



36. Murphy, N. C 8 1889 



37. Mt. Joy, Pa 385 1887 



38. Navajo, Ariz 1499 1921-1926 



680 



39. Nedagolla, India ^ 4.5 Jan. 23, 1870 



40. Negrillos, Chile 28.5 before 1936 



41. Nenntmannsdorf, Saxony 12.5 1872 



42. Okano, Japan 4.74 Apr. 7, 1904 



43. Opavo, Czechoslovakia 7.4, 5.8, 1925 



1.0, 0.1 



44. Otumpa, Argentina (15 tons, 1576 



est.) 



45. Pima County, Ariz 0.21 before 1947 



46. Pirapora, Brazil ^ 2.56 



47. Puripica, Chile 19 1929 



■* "A cart would be required for its carriage," G. A. Daubree, Compt. Rend., 

 Acad. Sci. Paris, vol. 81, p. 597, 1875. 



5 Although reported as a nickel -poor ataxite, the analyses show 6.2 and 6.1 

 percent of Ni. These values are above the Ni content of hexahedrites. This 

 iron, which has exceptionally fine flight markings, obviously fell as an orientated 

 individual. A cross section through its short dimension shows two well-defined 

 heat-altered zones about 2.5-3.0 mm. wide. The metal between these thermally 

 altered zones displays a pattern like that formed when metal is rapidly quenched 

 (Axon, 1962). This structure is visible at low magnifications (6X to lOX) ; 

 however, at higher magnifications a granular texture is noticeable. Both struc- 

 tures existed before this meteorite entered our atmosphere. 



All witnessed falls of hexahedrites (table 2) occurred in the morning. Neda- 

 golla fell at 7 p.m. Meteorites falling in the morning are oncoming ones, thus 

 enter the atmosphere with higher velocities than those which fall in the afternoon 

 hours. Hence, the Nedagolla differs from the witnessed hexahedrite falls not 

 only in its metallography and chemistry, but also in the time of fall. 



To combine two interpretations, one from its chemistry and the other from 

 its metallography, to explain its past history, is difficult. The structure, notice- 

 able at low magnifications, is that of a metal which solidified quickly, but the 

 granular texture, visible at higher magnifications, is suggestive of later reheat- 

 ing to about 800° C. Where and when these events took place is unknown, but 

 they happened prior to its fall in 1870. From its chemical composition this iron 

 might represent a melted coarse octahedrite, and it is definitely unlike all other 

 hexahedrites. 



' The Pirapora, Brazil, iron was reported in private communications from 

 Dr. Walter Curvello, Museum Nacional, Rio dc Janeiro. No additional data 

 are available. 



