Chap. II. ] 
UST OF MANGANESE MINERALS. 
23. 
often in igneous rocks, rarely in mineral veins, and probably never in 
sedimentary rocks. The niobates, tantalates, and tungstates, are found 
either in igneous i veins, whilst the phosphates, arsenates, and antimo- 
nates, probably occur in both igneous veins and metamorphic rocks. 
The titano-silicates are also found in igneous and metamorphic; rocks. 
Of the large number of manganese minerals known, only a moderate 
proportion has been found in India. Taking into acco ant, however, the 
considerable variety of the Indian manganese minerals yet found — includ- 
ing members of the groups of oxides, manganates, carbonates, silicates, 
phosphates, arsenates, niobates, and tungstates — , and the fact that the 
list of Indian manganese minerals is being constantly extended, one 
may expect to find almost any of the manganese-bearing minerals 
met with in other parts of the world. Consequently I propose to give 
here a list of aU the weU-defined minerals containing a considerable 
proportion of manganese, together with the formula, crystal system, 
specific gra'vity, and hardness of each. The figures given in this list as 
well as the formulae, are almost all of them taken from the sixth 
edition of Dana's System of Mineralogy, its Supplement, and 
Appendix. 
Table 2. 
List of knoicn manganese minerals loith their chief properties. 
Name. 
Formula. 
Crystalline 
system. 
Specific- 
gravity. 
Hardness. 
Sulphidea — 
Alabandite 
Hanerite 
1 
MnS .... 
MnS" .... 
T. Tetrahe- 
dral. 
dral 
3 -95-4 -04 
3-46 
3-5-4 
4 
Chlorides — 
Scacchite 
ilna2 .... 
Oxides^ 
Manganosite . 
3InO 
I. . 
518 
5-6 
Pyrophanite . 
Bixbyite . j 
ilnO.TiOo 
FeO. Mn02 
in. Rhomb- 
tetartohe- 
dral. 
I. . 
4-51 
4-95 j 
5 
6-6 5 
1 lacludiag ' aqneo-igneoas ' vems. 
