Gold
Gold occurring in various geological formations in Poland was a subject of a mining activity from at least the early Middle Ages. At present, gold is extracted only from copper-silver deposits located in the area of the Fore-Sudetic Monocline. Gold occurs mainly in the oxidized facies sediments (in German Rote Fäule), mainly in rocks of the Weissliegendes Sandstone of the Rotliegend and in the lower parts of the Zechstein copper-bearing schists (Kupferschiefer). Gold is recovered in the course of a technological processing of sulfide ores and imported inputs. In 2020, 878 kilograms of Au were recovered from Polish sulfide Cu-Ag ores. However, taking into account the recovery from the imported inputs – there were about 3,011 kilograms of Au recovered.
The gold and arsenic mine at Złoty Stok, closed in 1960, was the biggest active gold mine in the Sudety Mts. Documented in 1954 gold resources of Złoty Stok deposit were estimated at 2,000 kilograms in the ore anticipated economic resources and 490 kilograms in the ore anticipated sub-economic ones. The mean content of gold in löllingite-arsenopyrite ore is 2.8 g/t of ore. This deposit was exploited after the Second World War in 1954-1960. During that period about 25% of documented resources were exploited.
In 2020, there was the geological documentation of the small deposit of gold ore in kaolin clays approved – Mikołajowice in Dolnośląskie Voivodeship. In the deposit there were anticipated economic resources in C category documented - they are equal 5,028.7 thousand tonnes of ore, 968.0 kilograms of metallic gold and 723.8 thousand tonnes of kaolinite; the anticipated sub-economic resources also documented in C category are equal 4,842.6 thousand tonnes of ore, 69.7 kilograms of metallic gold and 435.8 thousand tonnes of kaolinite. The deposit is formed by one bed of kaolin weathering loams with quartzitic debris – the result of quartz-micaceous schists and quartz-feldspar veins weathering processes. The average content of gold in the anticipated economic ore was geochemically determined at 172.4 ppb, whereas in anticipated sub-economic ore at 14.4 ppb.
The prospective resources of gold in Poland are assessed to be equal 419.2 – 431.8 tonnes, whereas the prognostic resources to be equal 34.3 tonnes*.
Prepared by: Stanisław Z. Mikulski
* Mikulski S.Z., Oszczepalski S., 2020 - Rudy złota (gold ores). In: Bilans perspektywicznych zasobów kopalin Polski wg stanu na 31.12.2018 r. (eds. Szamałek K., Szuflicki M., Mizerski W.): 174-187. PIG-PIB, Warszawa [in Polish].
Table 1. List of gold deposits