Remember the Rainforest 1
through a beautiful, mountainous and very varied region of fields, but deserted, in which we passed two small farms, Laranjal and Pires. Thick deposits of mica schist, containing oligyst or crust of the iron ore layers, are here as the upper mountain formation, above clay or quartzite. In both are an extraordinary amount of magnetite octahedra and pyrite crystals, which have become iron ores; Recent pyrite and large leaves of oligysts lie scattered on the road.
At noon we arrived at the Forja de Prata or Silver Forge, five leagues east of Capao.
Silver forgers by Goya
This plant, founded as a company under the auspices of the previous governor, Count de Palma, by our compatriot von Eschwege, produces, in four Swedish ovens and two bar ovens annually, some one thousand wrought iron arrobas, of which much is prepared on site. A rich oligyst is mined, and above all magnetite, whose deposit occurs in great thickness in the vicinity of the forge. The inspector of the iron forge accompanied us the next day to the mining, one and a half leagues far to the southeast, belonging to Mr. Romualdo Jose Monteiro de Barros, the goal of our trip. Here we were welcomed by the owner, a colonel of militias, with the miner's own generous hospitality. After the midday meal, he brought us to his mine, whose formation is not of mica schist, containing oligist or tapanhoacanga, but an isabel yellow clay shale in which crosses of quartz contain gold.
The main deposit runs north to south, and is one to twelve inches thick. The metal in the cracks is covered with a ferrous cap containing limonite, friable quartz so finely divided that the particles of its powder cannot sometimes be recognized with the naked eye. The deposit is, in some places, extraordinarily rich in this metal. In our presence, a black man, washing a fist-sized piece of quartz and breaking it with a hammer, obtained a visible portion of very fine gold worth a hundred cruzados. Also the clay shale, which in the crevices is also covered with earthy manganese peroxide, and often a black dendrolite, contains gold; but in this mine only the quartz strands are being explored. To unravel them, the owner has descended the mountain in various places, through violent jets of water, and with that has produced such steep ravines in the crumbly stone that one can scarcely, without danger of collapse, continue through to the veins deep inside.
It would be much more advisable to do systematic exploration with staked galleries and open wells. The gold obtained here is generally twenty-two carats.