Jasper is an opaque form of Chalcedony. It usually comes in shades of red, yellow, brown, and green, although there are rare forms of blue Jasper.It often contains organic material and mineral oxides which give it interesting patterns, bands, stripes and colors. Many of these patterns resemble landscapes with mountains and valleys.Jasper was a favorite gem in ancient times, and was believedto be protective, and ward off evil spirits. In folk medicine, it is rumoredto be of help for sciatica and troubled toenails.