Rocks and minerals

The earth's crust is made of rock masses. The highest mountains in Poland - the High Tatras and the Karkonosze Mountains in the Sudetes made of granite, The Eastern Tatras and the limestone belt between Kraków and Częstochowa, the highest parts of Lysogória are made of quartzites, volcanic cones, rare in Poland, such as "Czartowska Skała" in Lower Silesia, made of basalt, and the vast plains of Mazovia mainly of clay, sand and gravel. These are rocks that we use for a variety of purposes. In cities, we walk on cobblestones or granite paving slabs, porphyry or basalt. They were built of easily split limestone, and in many countries houses and farm buildings are still built today. Sandstones and multi-colored marbles are used as wall cladding in buildings and palaces. Plastic clays for making bricks, and loose sand and gravel for making artificial rock-concrete. Some rocks, edible clays until recently saved Bolivian Indians from starvation in times of disaster and lack of game.

Man has been interested in rocks since the earliest times. History proves it, even the oldest "written."” archaeological excavations. In the period when iron was not known, bronze or even ordinary, soft copper, people also needed tools. Spearheads, with which it was necessary to "hunt food."”, knives for processing leather into clothing, hatchets and weapons to protect against predators, and later agricultural implements and tool making tools.

Various materials have been tried. Sharpened by rubbing against sandstone a stick that is broken from a tree, animal bones, and even larger and smaller stones, as rocks are often called in colloquial language. It was quickly noticed, that the stones are different: soft and hard.

Our ancestors used flint – hard mineral, but fragile at the same time, easily splintered into smaller pieces with sharp edges like a knife or saw. Flint was created from the remnants of living organisms, like for example. sponges, which included silicon compounds. That is why it comes in the form of smaller or larger lumps, called buns, in limestone sedimentary rocks. Initially, these pieces were collected, which occurred from the surface of the rocks. Later, when these began to be lacking, a more detailed search began.

It was quickly convinced, that in places, where there are single stones on the surface, it is worth digging deeper. It even turned out, that flints extracted from deeper layers of limestone are better. Not weathered by the action of the sun, water and air, more workable, they could be used as tools for longer. Thus mining was born and geology was born – earth science (Greek geo = earth and logos = word, science), about rocks and minerals, mines began to emerge. But many years have passed since the first use of stone tools to build the first mines. The oldest flint tools in Poland, manufactured in the flint processing workshop in Strzegowa near Olkusz, are about 50 thousand years. The first real mines only or as much as 7000 years. Such mines have been discovered in Poland over more than 20. Among them, the largest and best-preserved mine in Europe in Krzemionki Opatowskie. Over a huge area of ​​length 4 km and width from 40 do 1 20 m our ancestors dug over 700 shafts deep 5-6 meters, and from each of them many, horizontal mining corridors with a length of several to several meters. Characteristic flint was mined in this mine, easy-to-recognize patterns. The excavated flint was split into flat wedges, they were bruised until they gave the shape of an ax, and then sanded on sandstone slabs. Judging by the numerous finds, a significant part of these axes were exported as far as the Elbe in the west, to Rügen in the north, and to Moravia in the south.