There is information about the jasper on an information board
The jasper
The jasper is a microcrystalline variety of the mineral quartz. Other microcrystalline quartz are e.g. agate or chalcedony. Typical of the jasper is the high proportion of foreign substances (proportion of foreign substances up to 20%, e.g. iron oxide). Its special features, such as complete opacity and mostly intense coloring, are based on the large amount of these foreign constituents. The amount and distribution of the admixtures determine the appearance of the jasper, for example, they determine the hue, line color and pattern. The range of colors and varieties is therefore extraordinarily large. The most common are brown, red and yellow shades. The jasper is only rarely monochrome, usually several colors or shades of color occur, either regularly alternating in parallel / concentric layers, or distributed in veined, flamed or irregular patterns. Source: Text information board
The jasper: localities and use
In the Bible the jasper is mentioned as the first cornerstone of the city wall of the heavenly Jerausalem (Rev 21:19). The jasper was already valued as a gem stone in ancient times and used for mosaics. It was still used extensively in the Middle Ages. Over the centuries, however, the stone has lost its importance, so that in modern times it was mainly used for boxes, vases, table tops or mosaics. The jasper is either stored in layers in other rocks or in irregularly defined tubers. Locations of the jasper: e.g. North America, Urals, India, Egypt, Germany (on the German Gemstone Road, in the Ore Mountains, in the Harz as well as in Baden). The origin of the gemstone industry in the region around Idar Oberstein goes back to raw stone deposits of agate, jasper and amethyst, which were created through volcanic activity. Red, yellow and green jasper can be found along the copper-jasper trail. The dismantling of these jasper tunnels temporarily formed the economic basis of the Niederwörresbacher grinding shops. Source: Text information board