Back to Materials Carnelian Carnelian is a type of quartz (silicon dioxide). The strong red colour comes from iron oxide impurities. Carnelian comes is several colour types. Dark red, light red/brown, flashed with white streaks etc... These are all commen types of carnelian. The carnelian we use is african carnelian. The colour is quite uniform, and allows us to create more stable designs that we can replicate. India is good source of carnelian, believed to be some of the oldest on the planet, but it can be found all around the world and is a moderately priced semi-precious stone. Carnelian has a specific gravity of approximately 2.60 (2.60 times the weight of water by volume) which is slightly lower than the average value for quartz minerals, and its hardness value is 7.0 on the mohs scale.