Georgius Agricola (1546.)

Gravel

Gravels are utilized firstly by building industry. The high-quality sand is used for water filtering, chemical filtering and park constructions. The gravel can be formed through any physical rock- crumbling, its breaking into small pieces and transportation of rubble.
If you examine the components of gravel layers or bed deposits in rivers, you can see that the material of gravel is mostly quartz and quartzite. The reason of this is that among the mineral components of rocks the most resistant against physical and chemical effects is quartz. Being so, it can take longer transportation and thinning than any other rock component.

The quality examination of gravel is very important in gravel-mining, since for concrete production only the gravel featuring the determined characteristics is useable. Therefore size of grain; mud, lime and organic matter content and its mineral components are examined. For meeting the widest scale of demands possible gravels are classified by grain size.

Sand

Sand is used in the building industry for making plaster and concrete. We mine the sand from eocene, oligocene, miocene and pannon layers, and pleistocene accumulations in rivers.

The dead

The dead is used for foundations of road constructions. Foundations are done with rough rubble then it is covered with finer (about 2 cms) basalt or andesite rubble bedded in asphalt.