12 Field Museum of Natural History — Geology, Vol. V. 



it has a reddish color, indicating a higher oxidation of iron at these 

 points. The color of the interior of the stone is gray, more or less tinged 

 with brown from iron oxide. The texture is compact and so firmly co- 

 herent that it can be broken only with difficulty. Surfaces take a good 

 polish. There is an abundant admixture of metallic grains in the stone. 

 These are of small size and uniformly distributed. As seen on a polished 

 surface they are very irregular in outline but at times elongated. They 

 rarely exceed yi mm. in diameter. Nearly all consist of nickel-iron but 

 a few show by their yellow color that they are troilite. The siliceous 

 ingredients of the stone are largely in the form of chondri, plainly 

 distinguishable on a polished surface by their circular outlines. Some 

 of the chondri are black in color, others are dark gray and others light 

 gray. The largest chondrus noted has a diameter of 2 mm. ; the average 

 are about half that size. The chondri as a rule break with the stone but 

 occasionally separate out, especially on polished surfaces. The mega- 

 scopic characters seem to place the stone in Brezina's class of spherulitic 

 chondrites. 



Under the microscope, chondri are seen to largely characterize the 

 structure of the meteorite though their quantity is not as great as in 

 some meteorites. The ground mass is for the most part well crystallized, 

 the crystals being large and with definite outlines. The prevailing min- 

 erals both of the chondri and ground mass are chrysolite and enstatite, 

 chrysolite being the more abundant of the two. The chondri present the 

 usual porphyritic, radiated and lamellar forms. Of especial note among 

 the lamellar forms is one in which the lamellae run in three directions at 

 angles of 6o°. The three series of lamellae have different extinction 

 angles and the border zone extinguishes in unison with one set of the 

 lamellae. 



The crust is thin for a meteorite so coarse in structure and nowhere 

 in the sections examined by the writer shows an absorption zone. The 

 outer or fusion zone is very nearly one-tenth of the thickness of the 

 impregnation zone. The thickness of the two zones combined approxi- 

 mates closely to 0.4 mm. The impregnation of fused matter from the 

 surface due to the formation of crust affects the ground mass but does 

 not penetrate the chondri. 



MACQUARIE RIVER 



This locality (spelled " Macquaire " River) was listed in the appendix 

 of Wiilnng's catalogue* and specimens were mentioned as possessed by 

 Gregory, 58 grams, Paris School of Mines, 1 gram, and v. Siemaschko, 



* Die Meteoriten in Sammlungen, Tubingen, 1897, p. 402. 



