Before the use and general spreading of metals an essential part of the tools were made of 'stone', typically, hard, lasting and easy-to-flake silex.
The Tűzköveshegy (Flintstone Mountain) at Szentgál is one of the richest natural sources of silex in Hungary. The rock exploited here - by its exact geological name, radiolarite - supplied the Northern parts of Transdanubia and regions beyond with good quality lithic raw material.
Radiolarite belongs to the family of siliceous rocks. It is composed of micro- and cryptocrystalline quartz and chalcedony. The bulk of the rock is built up from the skeletal elements of siliceous microfossils called Radiolaria.
This rock is formed in the deepest regions of tropical and subtropical oceans. During the Jurassic period, the large equatorial ocean called Tethys accumulated incredible amounts of these beings which can be found today in the form of radiolarite belt from Spain till the Himalayas along the Alpean mountain system.
Radiolarite as a rock is quite widely distributed. Its quality, however, is essentially influenced by local geographical and geological conditions. The radiolarite of the Tűzköveshegy is of specially homogeneous character, void of tectonic fractures. It is found here in vivid attractive colours (red, yellow) which is not typical for other geological sources. Its bedrock is called after its raw white colour and porose texture
porcellanite, wwhich is composed basically of opal-CT and can be exploited more easily than the radiolarite found in the siliceous limestone layers of the Gerecse Mountains.
Favourable strike and easy transport conditions at Szentgál- Tűzköveshegy (the former mining area lies along currently important international mainroad and railroad lines) probably contributed to the formation of the largest workshop and exploitation area complex in Hungary.
