96 rERIDOTITE. 



The enstatite, pyroxene, and olivine are in clear grains when unstained, and are much 

 fissured and broken. 



Some of the enstatite shows the same structure as the chondri of other meteorites 

 except that it wants the cementing base. That is, these grains are formed from minute 

 orains arranged in rod-like forms, and lying side by side. The iron and pyrrhotite is in 

 irregular masses and granules. Some colorless irregular patches were observed, giving 

 a pale color in polarized light and resembling nephelite. 



Fio-ure 1, Plate IV., shows the general structure of the groundmass, with its inclusions 

 of iron, pyrrhotite, etc., and its ferruginous staining. This groundmass is fine-granular, 

 with some traces of chondritic structure. 



Mocs, Tnnwjlvania. 



This meteorite lias been described by Koch, Tschermak, and Brezina, and the follow- 

 ing is condensed from Tschermak's description. On the fresh fracture the rock appears 

 as a gray and white, rough, friable mass, flecked with little brown and yellow spots, and 

 traversed by fine black veins. The grayish-wliite groundmass contains small spherules 

 of varying size, small grains of iron and pyrrhotite, and occasionally larger grains of iron. 

 Those chondri which are granular and vary from a white to a yellowish color are com- 

 posed of olivine, but those of a white color and of a fine rod-like or fibrous texture are 

 composed of enstatite. Under the microscope the stone was found to contain olivine, 

 enstatite, diallage, plagioclase, iron, pyrrhotite, rarely chromite, and a black undetermined 

 mineral. The olivine is pale-yellowish green, and contains irregular inclusions of a fine 

 black dust, angular black grains, and glass. The enstatit'^ has a pale-greenish color, and 

 contains brownish, rounded glass inclusions, spherical and lens-shaped vapor cavities, and 

 small black spheres. The diallage contains inclusions of abundant black dust and grains, 

 and glass, with some microlites. Part of the diallage presents the characters of diopside. 

 The plagioclase appears in colorless rounded grains, containing many irregular, brownish, 

 glass inclusions. In polarized light many of the feldspars show well-marked character- 

 istic twinning. The iron is in small spheres in the groundmass and in the chondri, as 

 well as in rounded and elongated rough grains, sometimes showing a cubic cleavage. 

 The pyrrliotite occurs in n)inute grains.* 



Zsaddivj, Temesvar Comitat, Banat. 



Dr. E. Cohen made a microscopic study of the Zsadany meteorite in 1878. Macro- 

 scopically, the following constituents were observed: — 



1. A fine-crystalline, light-gray groundmass, in which appeared scattered grains with 

 a conchoidal fracture and a vitreous lustre. These were mostly water-clear or else of 

 a pale honey-yellow color. 



2. Grains of the color of pyrrhotite, and grains or leaves of nickeliferous iron. 



3. Numerous dark gray crystalline spherules, with a rough surface, and a faint 

 resinous lustre on the surface of fracture. On the polished surface they show an 

 elliptical form. 



In the thin section two classes of these spherules were seen. One is composed of 

 small columns of an enstatite-like mineral. This contains a few small pores, and 



* Koch, :\riii. Mitth., 1S83, v. 231-244; Sitz. Wien. Akad., 1882, Ixxxv. 1, pp. llG-182 ; Tsclicnnak, 

 ibid., pp. 195-209 ; Brczina, ibid., pp. 335-313. 



