364 PROCEEDINGS OF THE NATIONAL MUSEUM. 



I II 



Per cent. Per cent. 



Silica (SiOj) 49. 50 49. 59 



Ferrous oxide (FeO) 15.88 17.01 



Magnesia (MgO) 33. 01 32. 51 



98.39 99.11 

 These closely agreeing results he felt justified him in considering 

 the mineral a new species, to which he gave the name PeckJiamite. 

 S. Meunier^ also studied the meteorite, recognizing the presence of 

 olivine, bronzite, and a triclinic feldspar, and suggested that Smith's 

 peckhamite was not a new mineral species, but a result of "the 

 union of alternate laminae of extremely thin bronzite and olivine." 

 Tschermak,^ who studied the stone in thin section, recognized the 

 occurrence of olivine, bronzite, and plagioclase. The bronzite he 

 described as having in part the usual appearance, with few inclu- 

 sions, and in part as clouded by fine dust and showing large glass 

 inclusions. These turbid grains he assumed were of the same nature 

 as Smith's peckhamite, which he described as showing the prismatic 

 cleavage of bronzite, but giving also cleavages which could be re- 

 ferred to the crystal faces of olivine. The optical characters were 

 described as almost similar to those of bronzite. "The v/hole sec- 

 tion," he wrote, "is clouded by a fine dust and also contains larger 

 inclusions of two kinds. One variety is in the form of dark brown 

 to black spheres, the other rod-like or spindle-like colored glass in- 

 clusions which correspond to negative crystals and similarly colored 

 round glass inclusions. A glance suffices to show that the substance 

 is a mixture, and the analysis does not give me a result which corre- 

 sponds to a single mineral." He concluded as a result of his studies 

 that the so-called peckhamite was a bronzite rendered turbid and of 

 a glassy luster by a great quantity of inclusions. In this he was 

 apparently correct. Wadsworth, who was the last to publish the 

 results of a microscopic examination, reported the presence of dial- 

 lage in addition to the other minerals mentioned, and agreed with 

 Tschermak as to the nature of the peckhamite. 



My own investigations were instigated by an examination of a 

 fragment of the stone in the Shepard collection, around one portion 

 of v/hich had been painted a yellow ring, indicative of some unusual 

 feature to which evidently it was wished to call attention. Exam- 

 ination showed this ring to include a ^^ellow-brown, opalescent mineral 

 which it was at once apparent was the original mineral called cltas- 

 signite by Shepard, and pecJchamite by J. L. Smith. The unusual ap- 

 pearance of this mineral was sufficient to warrant further investiga- 

 tions, the results of whrch are given below. 



The pyroxenic constituents of the stone are of more than ordinary 

 interest and were the first to receive attention. Examination with a 



» Compt. Rend., vol. 94, 1882, pp. 1659-1661. « Photographien. pp. 22 and 23. 



