92 PERIDOTITE. 



The choudri are composed principally of olivine and enstatite, and show the usual 

 variations ; but for the descriptions the reader is referred to the original paper.* 



Goimlpuv, India. 



The Gopalpur meteorite was microscopically studied by Tscherma.k. Its color is 

 grayish-brown, but in the interior whitish-gray. The groundmass is filled with numer- 

 ous little spherules, which are of a brownish-gray or a clear gray color. Throughout, the 

 groundmass glitters with yellowish points of pyrrhotite. Cellular, pronged grains of iron 

 could be seen in the section. 



This meteorite belongs to the chondrites of Eose. The whitish groundmass is 

 earthy, tufaceous, containing angular fragments of anisotropic minerals of various sizes. 

 The larger fragments show a fibrous or stalk-like structure with an evident cleavage 

 parallel to their longer direction ; or they are traversed only by irregular fissures. The 

 groundmass contains particles of pyrrhotite and iron of various sizes. Immediately 

 about the iron is to be seen a small amount of a dust-like, untransparent, dark-brown 

 material which Tschermak regards as chromite. 



The larger spherules are composed principally of a radiating fibrous mineral, which is 

 taken to be bronzite (enstatite). Sometimes a granular mineral was observed in them. 

 Other spherules are made up of irregular fissured grains which are referred to olivine ; 

 and still others are thought to be composed of feldspar. From the figures and descrip- 

 tions given, the present writer thinks that the presence of feldspar is doulitful, although 

 Tschermak is one of the best authorities on that point. The author hopes that a careful 

 re-examination of the sections will be made. 



The large, dark, opaque particles in the spherules and groundmass are iron and 

 pyrrhotite. 



The spherules are said not to be difTerent in composition from the groundmass. In 

 both can be recognized, as the essential constituents, bronzite (enstatite), olivine, iron, and 

 pyrrhotite. The only difference is tliat in the spherules the crystal grains are smaller. 



Tschermak holds that the chondritic structure displayed in this meteorite was the 

 result of a mutual attrition of tlie different particles, tlie whole afterwards being cemented 

 together. He regards the whole structure as different from any terrestrial structure yet 

 observed.! 



Bufmra, India. 



The Eutsura meteorite was described by Professor N. S. Maskelyne in 1863, as having 

 a yellowish-brown groundmass containing numerous points of metallic iron. Irregular 

 dark stains were observed surrounding the iron. The iron is very evenly distributed in 

 small, isolated, irregularly formed and sometimes crystalline looking particles. Under 

 the microscope the chief mass of the meteorite was regarded as olivine, associated with 

 a gray and an opaque white mineral. The gray mineral constitutes entire nodules in 

 the meteorite, and sometimes seems mingled in the apparently brecciated mass, con- 

 taining olivine ci'ystals that form other nodules in it. It presents the appearance in the 

 former case either of a dark mottled surface spangled with dark jjoints, or of a mineral 

 presenting very regular and minute parallel cleavage-planes, with dark-gray bars running 



* Mon. Berliu Akad., 1S79, pp. 750-771. 



t Sitz. Wieu. Akad., 1S72, kv. (i), 135-HG; Min. Mitlh., 1872, pp. 95-100. 



