In proximity to the city of Trent vein- agates were found which are remarkable less because of their color or their beautiful pattern. Their speciality is that chalcedony includes sulfides and their decomposition products. The included minerals can be differentiated partially on the basis of their colors: - realgare is red and resin-shining, stibnite among other sulfides - metallically grey and in the polished section silver reflecting, as well as decomposition products of these minerals in ocher tones.