Folia archeologica 45.
Tóth Endre: Dr. Soproni Sándor szakirodalmi munkássága
46 VIOLA T. DOBOSI-IS ÏV ÀN GAT T ER This process induced local concentration maxims in the neighbouring territories as well as hydrothermal transformation of volcanic and metamorphic rocks. The accompanying quartz formation was probably not very important in raw material supply. Only one type of formation can be considered as potential source for rock crystal: the precious metal - polimetallic epithermal mineral association occurring several places within the Carpathian Basin (Mátra mts., Gatter 1983, Tokaj nits., Molnár 1993, Stiarnická ints., Vihorlat-Gutin mts., Transylvanian Island mts.) A characteristic feature of this type of formation are overgrown elongated quartz crystals formed in the open veins, which can be occasionally clear. In these generations of crystals, large inclusions of gas and fluids (libelles) are frequently found, often in the size of some millimetres. These inclusions occur frequently together due to the boiling of the hydrothermal solutions. The exterior surface of the crystals is discontinuous, due to the fast crystal growth, often sceptrelike forms or skeletal forms appear. The most famous occurrence of this type is Sobov near Banská Stiavnica (Scopoli 1776). Previous preliminary studies Ъу Gatter (1986) seemed to support the presence of this type of rock crystal in the Hungarian archaeological material. Due to the relatively small size of crystals in this genetical type, it can be suitable only for small (Í-2 cms large) implements. Thus they are ill suited as a potential raw material source. 4. Hydrothermal quartz occurrences in sedimentary environment In special cases, sedimentary rocks can be cut by quartz veins, or certain sedimentary structural elements (cleavages or in drying forms) can be filled in, due to post-diagenetical hydrothermal processed. In the Carpathian Basin, we can enumerate two important examples: 1. The clefts of the Carpathian Sandstone (Miocene) are filled in by overgrowth quartz crystals, about 2 cm large, clear, with bulky but typical crystal form. This is the so-called "Maramarosh-diamond" type quartz variety which was collected extensively in former centuries for local purposes, ornaments etc. Localities where this type of quartz occurs include in Slovakia: Lendak, Spisske Staré Ves, Majerov, Vel'keho Lipnik, Zborov, Ulica (Tóth M. 1882, Hercko, I. 1984), in the Ukraine: Velikij Bickov, Mizshirja, in Romania: Ojdula (Gatter I., Szakáll S. in press). Typical features of this variety include a large number of hydrocarbon inclusions, in the first place, methane and ethane, together with water and oil drops, fhe microscopical characteristics of this type of quartz is quite simple, especially due to the non solvent methane-ethane inclusions and tlie oil inclusions. The characteristic form and small size of the crystals delimit other applications such as the production of stone implements. 2. In the Mesozoic sequence of the Mecsek mountains, quartz formations are known from several spots which can be considered as potential raw material sources. a./ In the Middle Triassic bitumen containing limestone and clay schist sequence, calcite and quartz veins with 1-20 cm large embedded crystals (Vető-Ákos E. 1980). The larger crystals are troubled, the smaller ones have a smoky tint. They can be characterised by CH and CO., inclusions. b ./ In the Upper Jurassic coal seam series there are sideritic septas, the characteristic mineral association of which has been published recently (Szakáll S., Gatter I, 1995, Szakáll S., Jánosi M. 1996). In these fillings one can find 1-3 cms
