Searching of flint sources and localization of places where once the Stone Age people obtained this raw material for tool making is an important subject of research not only in archeology, but in broader sense when exploring the ancient civilizations lifestyle, human migrations and interaction between ancient archaeological cultures, as well as tracing cognitive development, that covers not just simple geological observations and orientation in space, but also the first notions of material properties and their determination. Flint and its formation conditions are not the focus of particular attention in traditional geological studies today, since most of relevant studies have been carried out (Rykart 1989, Sieveking & Hart 1986), and their quality is still very high. In turn, the knowledge level of detail required for the results interpretation in ancient cultures studies is insufficient. Diversity of analytical measurements and divisive results so far failed to give reliable and convincing answers, because natural variations of flint properties cover significantly wider range of values than those identified in relevant artefacts. As a result, the current approach allows to relatively reliably detect only the local flint sources; in other cases just a general evaluation is possiblie. In the research of flint samples of different geological ages from several Northern Europe countries, as well as flint tools, material of artifacts collection from excavations of the Institute of History of Latvia were studied. This flint is mainly derived from the Jurassic and Cretaceous sediments, less Carboniferous and Devonian rocks, but an unique and distinct group consists of samples that cover chert and chalcedony saturated rocks. Such formations are quite widely known and are found in tectonic fractures and crack spreading zones in almost all rocks exposed in earth's surface, regardless of their geological age. In this study, the focus was on research methodology that would allow to find an approach to a more reliable flint source localization. The accumulated experience indicates the importance of sample macroscopic analysis and evaluation, including notes about characteristic inclusions, structural heterogeneity, typical fractures. The latter is particularly important because it contains a direct reference to rock cryptocrystalline structure properties, and was a relevant indication for ancient man about the possibilities to use such material for making tools. Without evaluation of the heterogeneity, the more detailed results of chemical and physical analysis may characterize variations of values rather than characteristic properties. In next stage of the research, it is appropriate to evaluate the sample in ultraviolet light (calibrated wavelength 365, using additional emission filter (485-655 nm). In this UV light it is possible to assess heterogeneity and to identify areas for future research. It is appropriate to study the selected areas of the samples additionally under microscope with a magnification of approx. 50 times. This allows to describe samples microscopically and to obtain more detailed data on inclusions, cracks, layers changes, etc., which can be saved in digital image format for further analysis. Only after this assessment, it is optimal to make detailed chemical and chemical-physical examinations, as the data obtained will be safely comparable. By following such a procedure, it is possible to identify many characteristics which allow to distinguish flint samples from different sites. However, it should be noted that the research carried out is still regional and it will require several more years of study to collect data on naturally occurring flint compositions and to create a corresponding database. At the same time, it should be noted that flint tools characterising the Stone Age archaeological cultures are made from different quality source material. The found material at many sites has been obtained quite remotely and not necessarily such "distant" material is of higher quality than the known local material. Perhaps, there had been sort of reserves or stocks that were carried, taking into account that not always it would be possible to find a suitable raw material. The choice of suitable raw material is the knowledge that was acquired very gradually, and therefore often rejects and mistakenly made tools can be found. However, although the knowledge about material properties was increasing, there was no tendency to use higher-quality flint raw material. Rather the opposite appears true - with more skills it was becoming increasingly possible to create higher quality tools from worse quality (less appropriate) materials. Additionally, it should be taken into account that in the historical course of time stone tools and their diversity was significantly changing, which required to search for a various quality raw materials. The overall tendency points to more pronounced symmetry of the tools, that are derived from cryptocrystalline flint types with small fractures, a material with very few inclusions and hidden cracks. The research results indicate that, following the proposed composition and properties, the investigation procedure (methodology) can identify characteristic and distinct features of flint samples, and they are indicative of to certain corresponding flint mining regions.