The land, through which we this day passed, appeared much burnt up, being in general very bare of vegetable soil, and having few trees to defend it against the heat of the sun. In the mountains we observed several slips or breaks, which presented abrupt and singular masses lying in all directions like confused heaps of architectural ruins, disclosing veins of soft talc, and some _cascalho_, poor in gold. The stratum was argillaceous schistus, very ferruginous, and friable. At the bottom of these slips, which appeared to be caused by the disrupture of one part of the mountain from the other (probably through the infiltration of water), there were small streams, which in rainy weather swell into torrents, and burst through their channels with great velocity.
The next day, it being our intention to reach Villa Rica before night, we set out at an early hour, notwithstanding the cold cloudy weather and the heavy dew which prevailed. We passed through a bare and uneven tract of country, presenting similar characteristics to those above described. Near a place called Capão, I rode down a hill covered with rich iron ore in such profusion, that tons might have been gathered from the surface. Proceeding a short distance farther, we arrived at a house, the owner of which, we afterwards understood, possessed a topaz-mine in the neighbourhood. The mention of a _mine_ of topazes excited my curiosity, as it gave me the idea of a vein worked under-ground, and containing those substances in the matrix as originally formed. On expressing to the owner my desire to see the works, he kindly undertook to accompany me to the spot. After walking about half a mile up the mountain just mentioned, I was shown two breaks or slips, in which my guide informed me were the topaz-mines. We entered one of them, which was in extent little short of two acres; the argillaceous schistus, which formed the upper stratum, appeared in a variety of stages, the greater part migrating into micaceous schistus. In one part I observed two negroes poking in the little soft veins, which the slips disclosed, with a piece of rusty iron, probably part of an old hoop; and on enquiring what they were about, I was informed they were the _miners_, searching for topazes. I took one of their instruments, and on using it as they did, found these veins to contain a very minute micaceous substance approaching to earthy talc, also some quartz, and large crystals of specular iron ore. I had the good fortune to find two or three topazes, which, as they had only one pyramid each, and appeared fractured, I judged to be out of their original place. It had hitherto been my opinion, that all the topazes which I had seen at Rio de Janeiro, or elsewhere, and which were of similar form to these, had been broken from the matrix by the miners; I now, therefore, fully expected to meet with some having double pyramids, but, to my great disappointment, all that I found were entirely detached. From a great quantity (at least a cart-load) of inferior topazes, which were afterwards shown to me in the owner’s house, (and any number of which I might have taken away), I could not select one with a double pyramid. They informed me that sometimes, but very rarely, topazes had been found attached to quartz, but even in these instances the quartz was fractured and out of its original place[36]. The topazes which were shewn me, were very imperfect, and full of flaws. The negroes employed in these works were superintended by two Creolians, who received what they found.