118 BULLETIN 94, UNITED STATES NATIONAL MUSEUM, 



to be referred to any crystal forms, since no zonal relations conld 

 be established after repeated measurements. The mineral is com- 

 monly brownish in color and only occasionally honey yellow. The 

 blebs are more or less cracked and the cracks filled with foreign mate- 

 rial, as graphitic iron, limonite, chromite, etc. Some of the clearest 

 grains, which under the glass were quite free from impurities, were 

 selected for analysis, with the following results: 



Per cent. 



Silica (SiO:) 85.70 



Magnesia (MsO) 42.02 



Ferrous oxide (PeO) 20.79 



Ferric oxide (FezOs) .18 



Alumina (Al.Oa) .42 



Manganese (Mn) .14 



Nickel oxide (NiO) .21 



Phosphorus (P) Trace. 



99.46 

 Reference.— W. Tassin, Proc. U. S. Nat. Mus., vol. 28, 1905,. p. 213. 



MUONIONALUSTA, NORTHERN SWEDEN. No. 424. 



Iron, Og. Slice weighing 107 grams, from a mass weighing 7.53 

 kilograms found in 1906. Analysis by R. Mauzelius yielded: 



Per cent. 



Iron (J^e) 91. 10 



Nickel (Ni) 8.02 



Cobalt (Co) .69 



Copper (Cu) .01 



Chromium (Cr) .01 



Phosphorus (P) .05 



Carbon (C) and sulphur (S) Not determined. 



99.88 



Nickel-iron was estimated to form 99 per cent of the mass, and 

 troilite and daubreelite 0.2 per cent. 



Gift of Geological Museum of TTpsala, Sweden. 



Reference. — A. G. Hogbom, Bull. Geol. Inst. Univ. Upsala, vol. 

 9, 1908-9, p. 229. 



MURFREESBORO, RUTHERFORD COUNTY, TENNESSEE. No. 99. 



Iron, Om. Slice, 3.2 by 2 cm. Weight, 57.5 grams. From a 

 mass weighing 8.5 kilograms or 18.7 pounds. Described in 181:8. 

 An imperfect analysis by G. Troost yielded : 



Per cent. 



Iron 96. 00 



Nickel 2.40 



Insoluble residue 1. 60 



100. 00 

 The nickel percentage is low and perhaps due to error in analysis. 

 Reference. — G. Troost, Amer. Journ. Sci., vol. 5, 1848, p. 351. 



