Note 90 — PETER KALM’s TRAVELS. (continued 2)

September the 2d. This morning we went to see the silver or lead veins. They ly a little on the south-side of the mills, belonging to the priests. The mountain in which the veins ly, has the same constituent parts, as the other high grey rocks in this place, viz. a rock-stone composed of a whitish or pale grey lime-stone, a purple or almost garnet-coloured quartz, and a black glimmer. The lime-stone is in greater quantities here than the other parts; and it is so fine as to be hardly visible. It effervesces very strongly with aqua fortis. The purple or garnet-coloured quartz is next in quantity; lies scattered in exceeding small grains, and strikes fire when struck with a steel. The little black particles of glimmer follow next; and last of all, the transparent crystalline speckles of quartz. There are some small grains of spar in the lime-stone. All the different kinds of stone are very well mixed together, except that the glimmer now and then forms little veins and lines. The stone is very hard; but when exposed to sun-shine and the open air, it changes so much as to look quite rotten, and becomes friable; and in that case, its constituent particles grow quite undistinguishable. The mountain is quite full of perpendicular clefts, in which the veins of lead-ore run from E. S. E. to W. N. W. It seems the mountain had formerly got cracks here, which were afterwards filled up with a kind of stone, in which the lead-ore was generated. That stone which contains the lead-ore is a soft, white, often semidiaphanous spar, which works very easily. In it there are sometimes stripes of a snowy white lime-stone, and almost always veins of a green kind of stone like quartz. This spar has many cracks, and divides into such pieces as quartz; but is much softer, never strikes fire with steel, does not effervesce with acids, and is not smooth to the touch. It seems to be a species of Mr. Professor Wallerius’s vitrescent spar90. There are sometimes small pieces of a greyish quartz in this spar, which emit strong sparks of fire, when struck with a steel. In these kinds of stone the lead ore is lodged. It commonly lies in little lumps of the size of peas; but sometimes in specks of an inch square, or bigger. The ore is very clear, and lies in little cubes91. It is generally very poor, a few places excepted. The veins of soft spar, and other kinds of stone, are very narrow, and commonly from ten to fifteen inches broad. In a few places they are twenty inches broad; and in one single place twenty-two and a half. The brook which intersects the mountain towards the mills, runs down so deep into the mountain, that the distance from the summit of the hill, to the bottom of the brook, is near twelve yards. Here I examined the veins, and found that they always keep the same breadth, not encreasing near the bottom of the brook; and likewise, that they are no richer below, than at the top. From hence it may be easily concluded, that it is not worth while sinking mines here. Of these veins there are three or four in this neighbourhood, at some distance from each other, but all of the same quality. The veins are almost perpendicular, sometimes deviating a little. When pieces of the green stone before mentioned ly in the water, a great deal of the adherent white spar and lime-stone is consumed; but the green stone remains untouched. That part of the veins which is turned towards the air is always very rough, because the sun, air, and rain, have mouldered a great part of the spar and lime-stone; but the green stone has resisted their attacks. They sometimes find deep holes in these veins, filled with mountain crystals. The greatest quantity of lead or silver ore is to be found next to the rock, or even on the sides of the vein. There are now and then little grains of pyrites in the spar, which have a fine gold colour. The green stone when pounded, and put on a red-hot shovel, burns with a blue flame. Some say, they can then observe a sulphureous smell, which I could never perceive, though my sense of smelling is very perfect. When this green stone is grown quite red-hot, it loses its green colour, and acquires a whitish one, but will not effervesce with aqua fortis.