ng, Me 
TS. Hunt on: Octahedral Oligist roi 313 
.s sk 
amination it was found to contain only oxyd of ‘occurs 
in an aggregate of white translucent. qua d feld- 
spar and dark green hornblende, the latter somet nes in crystals. 
The oxyd of iron is found alike imbedded in Il tk cies, in 
erystals which are seldom more than pine of an inch in di- 
ameter. ‘Their form is that of a regular eatabenon: generally 
with the mer bi pega ote often exhibiting the faces of the 
cube also in rounded “The crystals are frequently fi 
tied and the: iaibudad: oe are marked by delicate sfrie i 
three directions parallel to the edges. Color iron-black, oft 
with a bronzed tarnish; streak, purple-brown ; lustre, sub 
lic ; fracture, conchoidal, cleavage very” indistin net; n a “a 
even in powder. Hardness 6; gravity of crystals with some of 
the gangue still ‘adherent, 5 165; reduced to powder and washed 
to remove the accompanying silicious minerals, 533. ‘The crys- 
tals completely imbedded e boy homie) were like the others 
octahedral and non-magne 
he pulverized nicer 4 was resdity soluble in heated hydro- 
chloric acid, and the solution on dilution and boiling, deposited 
no titanic acid. The recent solution, air having been excluded, 
gave the reactions of a persalt without any traces of protosalt of 
iron, and the addition of ammonia precipitated peroxyd of iron 
from a colorless filtrate whith was not disturbed by sulphuret of 
ammonium or phosphate of swe ‘It was hence inferred that the 
mineral is pure peroxyd of ir 
The existence of these eink ifnbedded in unaltered dark 
green hornblende, a mineral which contains a lar ee amount of 
protoxyd of iron, and is so readily decomposed by the oxydating 
action of atmospheric influences, forbids the idea that they are 
pseudomorphs formed by the oxydation of ine the Sa 
e 
mula of anhydrous titanic al TiOz, the equivalent of bgt 3 will be 24, (omy 
be 1 The formulas 
gen==8,) and titanicwn corresponding to ferricum will formu 
different ilmenites and iserines will then _be fe 0, or ti our notation (fe, “i a 
the s of the two peroxyds jail very variable, and thus according, 
vie e, taniferous irons really examples of pero 
having the form and atomic volume of tite and-periclase. It is worthy o re- 
mark that the volume of og metric and rhombohedral og ae! A 
is same, ssimilati alumina ‘ sapph , > quartz, 
a ie : *hie a ae with specular iron, its 
we bird ithe formula al4O2, “§ which it ean — i in, i 
