Chap. XXXVni. 1 sandur State. 1017 
introduction ; the second stage is the production of wad from the 
altered phyllito, and sometimes direct from fresh ])hyllite by the intro- 
duction of manganese in solutitn, the wad retaining the original 
magnetite grains, lamination, and slaty cleavage, of the phyllite ; the 
third stage is the conversion of this wad into psilomelane, the latter 
retaining the magnetite grains and often the original lamination 
planes of the phyllite, but not its cleavage. Some of the psilomelane 
looses even this lamination. The tell-tale to this process is the 
magnetite, which seems to be the only mineral of the original phyllite 
that has been able to resist solution and replacement, and conse- 
quently to remain in the finished psilomelane. This psilomelane is the 
compact dull grey variety, with little sparkle about it, except when it 
contains the glistening points of magnetite. It does not all contain 
admixed wad. Thus in the Kamataru deposits the tendency is for the 
psilomelane to 'predominate, and the ores from this area are consequently 
of higher grade than those of the Ramandrug area, where the wad is 
much commoner. 
As might be imagined, the ore produced by this process is often 
cavernous. Sometimes these cavities have been 
pyS^rSies. filled With various minerals. One of the com- 
men est of these is the radiate fibrous mineral 
that I once described under the name of ' manganite 'i. As I have 
noticed on page 84 the analysis of this mineral since made by Mr. Fawcitt 
shows that it has suffered partial alteration into pyrolusite. I have 
consequently made use of name ' pseudo-manganite ' to express the 
fact that although it often has the physical properties of manganite 
to a large extent, yet it has usually been partly altered so as to be 
intennediate in composition between this mineral and pyrolusite. 
When in this intermediate condition it commonly shows a bronze 
tarnish. But it has frequently been still further altered with the 
production of radiate pseudomorphs of pyrolusite needles of rich 
black colour. Both these minerals may occur as radiations projecting 
freely into the interior of the cavities ; or they may occur as radiations 
in the mass of psilomelane or wad without 
psUomdaaa ^ ''"'^ there being any open spaces. In these cavities 
botryoidal, or even stalactitic, linings of psilo- 
1 Rec. G. S. I., XXXIII, pp. 229-232,(1906). 
