Page:The Journal of geology (IA journalofgeology11893univ).pdf/292
| Alumina (Al2O3) | 0.34 | |
| Cobalt oxide (CoO) | (not determined)[1] | |
| Lime (CaO) | 3.44 | |
| Baryta (BaO) | 5.65 | |
| Magnesia (MgO) | 1.26 | |
| Potash (K2O) | 0.35 | |
| Soda (Na2O) | none. | |
| Phosphoric acid (P2O5) | none. | |
| Tungstic acid (WO3) | 2.78 | |
| Silica (SiO2) | 1.70 | |
| Water and organic matter | 4.16 | |
| 98.97 | ||
| Metallic manganese | 50.85 | |
| Metallic iron | 2.32 | |
| Metallic tungsten | 2.20 |
It will be seen by the analysis that the ore is an impure oxide of manganese, being possibly a mixture of the peroxide and sesquioxide, though the impurities obscure its true nature. The most remarkable feature of the ore is the considerable amount of tungstic acid present, comprising 2.78 per cent of the ore and corresponding to 2.20 per cent of metallic tungsten. The form in which the tungsten exists in the ore is uncertain. It is possible that it may exist as a tungstate of manganese or iron, or of both, or perhaps of one of the other bases present. It may either have been deposited from solution with the manganese, or it may have been brought in as detritus from an outside source during the deposition of the ore, in the same way as the fragments of rock were brought into the deposit.
Though from a mineralogical standpoint the ore is impure, yet for commercial purposes the analysis shows a good grade of manganese ore, and the presence of the tungsten would give additional value to the ore in the manufacture of certain kinds of hard steel.
THE NATURE OF THE DEPOSIT.
The ore occurs as a lenticular deposit imbedded in a soft white or buff colored calcareous tufa which contains fragments of sandstone, shale and massive limestone similar to those found
- ↑ There is more than a trace of cobalt present but the amount was not determined.