124: MANGANESE DEPOSITS OF INDIA : MINERALOGY. [ PaRT I 
ores from the Central Provinces as carried out at the Imperial Institute, 
small quantities of carbon dioxide have been returned. In two cases, 
namely Pali (page 957) and Ghogara (page 964), the amounts of this 
constituent are larger than in the Gaimukh ore. This is, however, in all 
probability due to calcite and not to rhodochrosite ; for these ores occur 
in crystalline limestones. In the other cases, in most of which there is no 
indication of calcite in association with the ores, it may either mean that 
there is a very small proportion of rhodochrosite present, although this 
has not been detected in the ores of these places either macroscopicall/ oc 
microscopically or that carbon dioxide is in most cases really absent, 
the determination of its presence being due to experimental errors 
unavoidable when dealing with such small quantities of a substance so 
elusive as a gas. 
The one occurrence of this mineral in the Nagpur district is a doubtful 
one ; this is at Parsioni, where it seems to occur very sparingly in some 
of the rocks of the gondite series. The rock in which it occurs is composed 
mainly of rhodonite and spessartite, with a certain amount of amphibole, 
and sometimes orthoclase. The carbonate is to be seen clearly in micro- 
scope sections only, where it is sometimes intergrown with rhodonite, 
and sometimes right in the middle of the spessartite. 
