This is an advance summary of a forthcoming article in the Oxford Research Encyclopedia of Anthropology. Please check back later for the full article. Fire is one of the oldest technologies of humankind; indeed, the earliest signs of fire appeared almost two million years ago. Traces of early fire use include charcoal, baked sediments, and burnt bone, but the archaeological evidence is ambiguous due to exposure to the elements for hundreds of thousands of years. The origin of fire use is, therefore, debated. The first fire users might have been occasional or opportunistic users, harvesting flames and heat-affected food from wildfires. The art of maintaining the fire developed, and eventually, humans learned to make fire at will. Fire technology (pyrotechnology) then became a habitual part of life. Fire provided warmth and light, which allowed people to continue activities after dark and facilitated moving into colder climates. Cooking food over or in the fire improved digestibility; over time, humans developed a culinary technology based on fire that included the use of cooking pits or earth ovens and preservation techniques such as smoking the food. Fire could even help in the procurement of food—for example, in clearing vegetation for easier hunting, to increase the fertility of the land, and to promote the growth of certain plants or to trap animals. Many materials could be transformed through fire, such as the color of ochre for use in pigments or the knapping properties of rocks for production of stone tools. Pyrotechnology ultimately became integral to other technologies, such as the production of pottery and iron tools. Fire use also has a social component. Initially, fires for cooking and light provided a natural meeting point for people to conduct different activities, thus facilitating communication and the formation of strong social relationships. The social organization of a campsite can sometimes be interpreted from the artifact types found around a fire or in how different fires were placed. For example, access to household fires was likely restricted to certain family members, whereas communal fires allowed access for all group members. There would have been conventions governing the activities that were allowed by a household fire or a communal fire and the placement of different fire types. Furthermore, the social uses of fire included ritual and ceremonial uses, such as cleansing rituals or cremation. The fire use of a prehistoric group can, consequently, reveal information on aspects such as subsistence, social organization, and technology.

This study investigates and compares methods to quantify color changes in quartzite rocks after repeated heating episodes. We collected quartzite samples from the southern Cape coast, South Africa, and heated them three times in experimental fires. We recorded the colors of the samples before and after heating using visual observation, Munsell color notations, Munsell color notations converted to RGB values, and digital image analysis. The methods are also tested on potentially heated and potentially unheated archaeological samples from Klasies River main site, South Africa. It was possible to distinguish between unheated and repeatedly experimentally heated quartzite using visual observation and Munsell color notation, but a large proportion of repeatedly heated samples appeared unaffected by the heat. The digitally-captured color values best discriminated color changes after heating. Color values of repeatedly heated experimental samples overlap with color values of potentially heated archaeological samples.