THE METEORIC PE1UD0T1TE8. — LUKItZOIJ I K. 00 



granular to compact groundmass, containing nickel-iron, pyrrliotite, spherules, olivine, 

 white crystal grains, and chroinite. He states that the nickel-iron occurs in three ditler- 

 ent forms: in large grains, in laminae, and in ramifying, pronged grains sprinkled througli 

 the groundmass. The surrounding groundmass is sometimes stained, through the altera- 

 tion of the iron, to a brown color. 



The pyrrhotite occurs in small irn^gular grains and granules of a tombac-brown color, 

 which, through a slight alteration, cliange to a dark steel-gray. 



The chromite is in very small black non-magnetic grains, and only in minute 

 amounts.* 



The specimen purchased from Ward and Howell for the Whitney Collection has an 

 ash-gray color and shows a chondritic structure. It contains pyrrhotite and iron. 



Section : composed of a light-gray chondritic mass, containing grains of iron and 

 pyrrhotite. The groundmass is composed of olivine, enstatite, and some diallage. The 

 chondri are formed, in part, of grains and crystals of olivine and of enstatite, cemented 

 by a gray, fibrous base. Like those examined by the writer in other meteorites he regards 

 these as the product of an arrested crystallization in a rapidly cooling mass — the 

 solidification taking place before crystallization was complete. Part of the enstatite 

 cliondri do not show the usual eccentric structure, but a parallel, or sometimes a xery 

 irregular one. 



The arrangement of the pyrrhotite and iron about some of the chondri reminds one 

 of the similar arrangement of the rejected or " pushed out " material about tlie feldspars 

 in some andesites. 



The iron is in part outside of, and in part entirely surrounded by, the pyrrhotite. 



Figure 1, Plate III., shows a large chondrus at the base of the figure, composed of 

 enstatitic, aggregately polarizing, fibrous material. The form shows the rounded indenta- 

 tions seen by Tschermak in the Tieschitz meteorite, and at its upper portion blends with 

 the groundmass, although distinct from it elsewhere. Under the microscope its boun- 

 daries appear to be those of a crystallizing mass and not those of a foreign inclusion in 

 the groundmass. At the left of this chondrus is another radiating fibrous one, com- 

 posed of enstatite ribs cemented by connective tissue of gray base, holding metallic iron 

 grains. The remaining portions of the figure are composed of mixed chondri and the 

 constituents of the rock. 



Figure 2, Plate III., shows the structure of a chondrus composed of olivine, enstatite, 

 iron, base, etc., with its blending at the bottom of the figure into the groundmass. 



Figure 3, Plate III., shows the relations of a mass of pyrrhotite (troilite) to an 

 inclosed mass of metallic iron, and the whole surrounded by the chondritic groundmass. 



JVeiv Concord, Guernse/j Co., Ohio. 



A crystalline granular rock containing pyrrhotite and iron, and showing yellowish- 

 brown spots of staining around the latter. 



Section : a light-gray crystalline mass of olivine, pyroxene and enstatite, and con- 

 taining iron and pyrrhotite. The groundmass is stained a yellowish-brown in many 

 places. 



* See further tlie original paper of vom Rath. Abhandlimgen aiis dem Gobiete der Naturwissenschaftcn, 

 Mathematik, uiid Mediciii als Giatulaliousschriri der niedcrrhciuischeu Gosollscliart iVir Natur-uiid llcilkuiide 

 zur feier des fiiufzigjalirigea Jubilaums der kouiglich rhciuischeu Fricdricli-W'ilhchiis-Uuivcrsitat. Bouu- 

 Am 3 August, 1S68, pp. 135-161, with plalc. 



