Although jasper may contain clay, it is often classified between the micro-crystalline varieties of quartz. In its chemical composition it is similar to agate, but it is more opaque. The colors generally range from yellow, red, reddish brown to green.
Jasper bears many names, some referring to their matrix or to their origin, others to rivers and mountains and so on. Dune beads does love them all. More information @ http://dunebeads.com/en/jaspers-in-plural-part-1 in four parts.
Gemstone, black ocean jasper or black orbicular quartz, natural, 8x8 mm, round beads - Mohs' hardness 6.5-7.0 - one unit is +/- 19 cm and has +/- 23 beads
Gemstone, natural ocean jasper or orbicular quartz, purple dyed, 8x8 mm, round beads - Mohs' hardness 6.5-7.0 - one unit is +/- 19 cm and has +/- 23 beads
Gemstone, yellow brown ocean jasper or yellow brown orbicular quartz, natural, 8x8 mm, round beads - Mohs' hardness 6.5-7.0 - one unit is +/- 19 cm and has +/- 23 beads
Gemstone, rainforest jasper or rainforest rhyolite, Australia, natural, 8x8 mm, round beads – Mohs' hardness 6,5-7.0 - one unit is +/- 19 cm and has +/- 23 beads