Pochodzenie kamienia użytego do budowy wybranych twierdz na Dolnym Śląsku

A variety of rock material was used to build the walls of the Fortress in Srebrna Góra (Silver Mountain). Most of it was fine-grain laminated gneisses and mica slates quarried on site. The entrance to casemates and the frames of merlons and all corners, edges, and rain-pipes were made from beige or grey and beige sandstone from Radków or red-coloured sandstone from Czerwieńczyce. A detailed analysis of the stone material found within the entire fort showed, that though it varies somewhat in terms of colour, the petrographic features are represented by three types of rock: granites, gneisses, and sandstones. The basic material used for the construction of walls included fine-grained biotite granites from the Maciejowice, Malerzowice, and Starowice regions and also leucogranites and aplites from the Jarnołtów, Nadziejów, and Kamienna Góra regions. In addition to these rocks, fine-grained gneisses were also quarried and used that were part of the cover of xenoliths. Lightyellow sandstones from the Żelazno area in the Kłodzko Valley were most probably used for building window frames and vents.