Chap. VII. ] 
PIEDMONTITE, 
189 
Although this mineral is found only in areas in which rocks of the 
gondite series occur, it does not usually occur actually in the rocks of this 
series, but rather in the crystalline limestones of the same neighbourhood. 
Thus in the Nagpur district the mineral occurs in association with 
erystalline hmestones at all the locaUties except Maharkund, where the 
mineral was found in loose blocks of epidote-rock. At Kajlidongri and 
Jothvad, on the other hand, some of the occurrences of piedmontite are 
in rocks intimately associated with the rocks of the gondite series. 
Below I give a list of the rocks in which piedmontite occurs at each of 
the known localities : — 
Ghogara : — As granules and nodules, both in gneiss, composed of 
quartz, felspars, and some sphene, and in crystalline limestone ; some 
specimens show a • passage from gneiss into limestone, by the 
chemical replacement and alteration of felspars with the production 
of calcite (see Plate 10, figs, -"i and i). 
Junapdni, Junawdni, and Rdjkota. — As granules, in crystalline lime- 
stone containing quartz and mica (phlogopite?). 
Maharkund : — As fine-grained patches in epidote-rock, the rock, 
which was found in loose blocks, probably occurring in situ in associa- 
tion with crystalline limestones or p}TOxenic gneisses. 
Mohugdon : — As granules, in crystalline limestone containing also a 
small amoimt of quartz and sphene. 
Pali : — As granules and small patches, in crystalUne limestone usually 
containing quartz, and in fine-grained granulitic gneiss containing 
quartz, plagioclase, orthoclase, mica, apatite, sphene, and sometimes 
spessartite and a colourless amphibole (see Plate 10, fig. 2). In the 
latter rock there is often present a certain proportion of calcite of 
secondary origin forming at the expense of the felspars, 
Kdilidongri :— The mineral occurs here under two distinct circum- 
stances. (1) One occurrence is in a rock composed of spessartite, quartz, 
plagioclase, and orthoclase (?), the rock being a part of the ore-body 
and in process of conversion into manganese-ore. (2) The other is that 
mentioned on page 680 and illustrated in fig. 1 of Plate 18, where 
the mineral has been developed on the schistosity planes of some serici- 
toid phyUites, in the part of a sharp fold into which these rocks have been 
thrown where the pressure was obviously most intense, the other por- 
tions of the rock being free from this mineral. 
