HANDBOOK OF THE METEORITE COLLECTIONS. 



159 



Constituents. 



Silica(Si02) 



Ferric oxide (Fe203) 



Alumina (AI2O3) 



Magnesia (MgO) 



Iron(Fe) 



Nickel (Ni) 



Lime(CaO) 



Manganous oxide (MnO). 



Sulphur (S) 



Chromium (Cr) 



Loss 



Per cent. 

 39.00 

 17.5 



20.00 



17.75 



1.25 



100.00 



Per cent. 



38.00 



25.00 



1.00 



14.25 



17.60 



.40 



.75 



3.00 



100.00 



Gift of R. de Kroutschoff. 



Reference. — O. Buchner, Die Meteoriten, 1863, p. 21. 



TOLirCA (XiaTJIPILCO), MEXICO. Nos. 75, 204, 357, 396. 



Iron, Om. Weight 33,610 grams. (1) Etched slice some 16 by 20 

 cm., weighing 840 grams, showing distinct Widmanstiitten figures 

 and irregular nodules of troilite (pi. 35) ; (2) two complete individuals 

 weighing 530 and 735 grams, showing oxidized and pitted surfaces; 

 (3) end of mass weighing 1,050 grams and showing two large troilite 

 nodules; and (4) nearly complete individual weighing 28,458 grams, 

 with slab cut from same weighing 1,997 grams. Date of fall unknown. 

 Known as early as 1776. Numerous masses of meteoric iron, varying 

 in weight from 300 pounds to minute specimens, have been found in 

 the Toluca Valley, and it is highly probable that they all came from 

 the vicinity of Xiquipilco, in the State of Mexico. Many of these 

 masses were used by the native blacksmiths as anvils and for making 

 agricultural implements.^ The iron is described by Cohen and Wein- 

 schenk as consisting of : 



Per cent. 



Nickel-iron 95- 05 



Taenite 2. 45 



Schreibersite and rhabdite 1- 17 



Kamacite (?) -98 



Nonmagnetic residue • 35 



100. 00 

 The nonmagnetic residue contained siliceous particles, among which 

 orthoclase, plagioclase, feldspar, quartz, zircon, and pyroxene have 

 been determined, with possibly garnet and cordierite. Chromite, 

 apatite, and graphite were also found. This is the first meteoric iron 

 in which the presence of quartz crystals and apatite were proven.^ 



1 Eastman, The Mexican meteorite, Bull. Philos. See. Washington, vol. 12, March, 1892. 

 ait may be added that there is doubt concerning the occurrence of the quartz as an 

 original constituent. 



