MINERAL CONSTITUENTS OF METEORITES. 
365 
Silicic acid [99-21] 
Iron oxide &c 0-79 
100-00 
Besides the distinct cleavage parallel to the plane 001 already alluded to, and the other, 
less distinct, parallel to the planes of the form (101), there seem also to be divisional 
planes or, rather, surfaces along which the crystals break up with the greatest facility ; 
even drying them on blotting-paper proving often sufficient to destroy the integrity of 
specimens that might otherwise seem to promise good results to the goniometer. 
Partsch*, in his description of the Vienna Collection of Meteorites, identifies as a spe- 
cimen of the Steinbach siderolite a fragment with a label, “ Native iron, jagged and 
hackly, with quartz in grains and a yellow fluor-spar ” ( gediegenes , zcilinicht und zackicht 
gewachsenes Eisen mit kornichtem Quarz und gelblichtem Flussspath). 
BREiTHAUPTf , in his paper describing the Rittersgriin Siderolite, makes its chief silicate 
to be peridot. It is doubtless bronzite. In addition to troilite and schreibersite, he 
records the presence of “ another mineral the composition of which is not yet determined.” 
It should be mentioned that, with a view to test the relative solvent action of alkaline 
carbonates on quartz and the meteoric silica, weighed portions of each were digested with 
a ten per cent, solution of sodium carbonate for ten hours at 100° C. under precisely 
similar conditions. Of the quartz 7’843 per cent, had dissolved, of the Breitenbach 
silica 9-437 per cent. 
XV. Iron of the Breitenbach Siderolite. 
Of the other minerals forming the mass of this meteorite, namely troilite, some little 
schreibersite, chromite, present only in minute quantities, a crystal of which, however, 
was measured and gave angles corresponding to a regular octahedron, and, finally, the 
nickeliferous iron, which forms the sort of sponge-like skeleton that unites the whole, 
the last alone demands detailed investigation. 
Two analyses, the former by the lead process, the latter by the barium method, gave 
the following results : — 
I. 
II. 
Mean. 
Equivalent ratios. 
Iron . 
. 89-975 
90-878 
90-426 
3-229 
Nickel 
. 9-642 
8-927 
9-284 
0-314 
Cobalt 
. 0-383 
0T95 
0-29 
0-01 
100-000 
100-000 
100-000 
The equivalent ratios, it will be seen, differ but slightly from Fe : (Ni, Co) = 10 : 1. 
Some small amount of the above iron will have been present as troilite, which dissolved 
with the nickeliferous iron in the mercuric chloride. Copper occurs in the Breitenbach 
iron, but only as a trace. 
RubeJ, who analyzed the llittersgriin iron, found iron 87-31, nickel 9-63, and cobalt 
0-58 per cent. The material appears not to have been entirely free from silicate. 
* Die Meteoriten im k. k. Hof-Mineralien-Kabinette. Wien, 1843, p. 95. 
t Berg, und Hiitt. Zeitung, xxi. p. 321. i Ibid. p. 72. 
