标题：: Classification of lithic raw materials used for prehistoric chipped artefacts in general and siliceous sediments (silicites) in particular: the Czech proposal = Javaslat a pattintott kőeszközök készítésére használt kőeszközök osztályozására, általános tekintetben, különös tekintettel a kovakőzetekre és a kovás üledékekre
摘要：Lithic raw materials for chipped artefacts can be divided into five groups: a) siliceous sediments (silicites); b)
minerals of SiO2; c) natural glasses; d) clastic silica sediments; e) other rocks. Special attention has been
devoted to the most important group of siliceous sediments. It is proposed to use one-word term silicite as the
comprehensive one for all varieties such is chert, flint, spongolite, radiolarite, lydite, limnic silicite. As the flint
should be called only the silicite originating in Upper Cretaceous chalk (and may be in Lowermost Tertiary –
Danian limestones). Typical feature of silicites is a presence of microfossils in contradiction to minerals of SiO2
that include quartz, rock crystal, chalcedony, opal and their coloured varieties (smoky quartz, citrine, jasper,
agate etc.) and occur as filling of cavities in igneous rocks, hydrothermal veins or products of intensive
weathering. Natural glasses suitable for chipping are represented by obsidian, pitchstone and tektites. Clastic
(detrital) silica rocks are composed especially of quartz or chert clasts and incorporate quartz sandstones,
orthoquartzites and chert breccias. The group of other rocks comprises for example porcellanites and hornfelses
(thermally metamorphosed sediments), silicified woods, fine grained acid volcanics, silicified fossils etc.
