246 Sherzer—Native Sulphur in Michigan. 
about 0:2 gr. of this was prepared. ‘To remove the impurities, 
the material was treated with stronger hydrochloric acid, which 
also slightly attacked the schneebergite with the separation of 
silica. An analysis of the carefully cleaned material gave 
SiO, 35°45 per cent and Fe,O, 32°11 percent. The formula 
for this composition exactly tallies with that of a lime-iron 
garnet, as the following analyses show : 
Found. -Caleulated for 
f 108 3CaO . Fe.O3. 3S8i0.. 
SiO, ace is Bae ese, 35°43 
Fe,O, oy yen Ce 32°33 32°11 31°50 
GaiOwie Baas 32°58 uc eae 
It follows from this examination, with certainty, that the 
schneebergite in the collection here, of which there is a whole 
series coming from different sources, is nothing more than a 
very pure lime-iron garnet, topazolite. The ore specimens 
came from the same locality as those described by Brezina and 
analyzed by Weidel. In respect to the color, hardness, micro- 
scopic relations, crystal form and the iron and calcium content, 
our mineral exactly coincides with that described by Brezina, 
so we make the supposition that the schneebergite is a garnet 
of the above composition. Our mineral fused in the blast 
flame to a dark brown liquid, while Brezina gave his as infusi- 
ble. Our supposition is supported also by the circumstance 
that Brezina described the material as insoluble in acids; cal- 
cium salt of an oxy-acid of antimony would naturally be easily 
dissolved in strong hydrochloric acid. Apparently, on account 
of the small amount of very impure material which Weidel 
had, a mistake was made in the qualitative analysis. 
The occurrence is exceedingly interesting, as garnet is seldom 
found in simple octahedra, and, until the present, a completely 
non-aluminous topazolite, with the exception of that from the 
Mussa Alp, has not been observed. The iron precipitate was 
treated with pure freshly-prepared sodium hydroxide, but no 
trace of aluminum was found; also the mineral contained no 
magnesia. 
Munich, Bavaria, May, 1895. 
Art. XXV.—WNative Sulphur in Michigan ; by 
W. H. SHERZER. 
DurRine the past year interesting deposits of sulphur have 
been discovered in the Upper Helderberg limestone, of Mon- 
roe county, Michigan, of which, it is believed, no report has 
yet been made. Native sulphur has not been recognized as 
