Carnelian belongs to the quartz group of minerals, the second most abundant mineral group on earth. It is classified by its distinct colour and is defined as a red-orange to brownish-red variety of chalcedony quartz. Carnelian obtains its colour through iron impurities that form within colourless quartz crystal. Carnelian is an ancient gemstone, having been used since antiquity with written records dating back over 4000 years. Moh's hardness scale: 7