CHAPTER III. 
mmERALOGY—conUnued. 
Oxides. 
Pyrophanitc — Dysluite — Manganmagnetite — Hausmannite — Vredenliurgiie — 
Sitaparite — Braunite — Polianite — Pyrolusite — Manganitc. 
Pyrophanite. 
This mineral, of the chemical formula MnTiOs , was originally found 
at the Harstig manganese mine in Sweden, and has been subsequently 
recorded as occurring in the Piquiry manganese-ore deposit in Brazil^ 
In the course of the microscopic examination of thin sections 
of manganese-silicate-rocks from both the Central Provinces and the 
Kajlidongri mine, Central India, I have several times noticed a mineral 
of a blood-red colour, non-pleochroic character, and high index of 
refraction, that may very well be the mineral pyrophanite. It always 
occurs m such small quantities, just a flake or two, that it is aot 
possible to isolate any and subject it to chemical tests to conhrm this 
supposition as to its nature. 
Dysluite. 
This mineral, which is a zinc-manganese-spinel of the "^formula 
(Zn,Fe,Mn)0.(Al,Fe)203,was found in 1897 by Mr. C. S. Middlemiss of 
the Geological Survey of India in a felspar-rock containing corundum 
and sometimes biotite, muscovite, and, in one case, chrysobery. This 
rock occurs as veins ramifying through the elaeolite-syenite-gneiss 
between Sivamallai Hill and Karutapallaiyam in the Coimbatore dis- 
trict. According to Mr. Middlemiss2 the dysluite generally occurs 
in irregular masses or veinlets, but sometimes shows an attempt at 
the regular spinel form, namely the octahedron. The m.iueral was 
determined by H. H. Hayden, to whom it was forwarded from the field, 
the particular locahty for the dysluite thus determined be'iig IJ miles 
S.S.E. of Padiyur. Mr. Hayden reported the mineral to be a zinc-iron- 
1 O. A. Derby, Amer. Jour. Sci., XII, p. 21, (1901). 
2 Manuscript notes. 
