When bones are recovered in archaeological contexts, they are not the white shiny ones you see hanging in the back of museums. Nor are they always tinted brown from years in soil. Bones can be a number of colors including black, red, yellow, white or green. Sometimes the coloration can be due to natural processes within the soil, and sometimes they are an indicator of cultural activities. Color can be painted or stained directly onto the bone or can be placed on the skin and become imprinted on the skeleton following putrefaction. It can also be accidental but still due to the nature of the funerary rituals. Whenever a bone appears to have a difference in pigment, or there is variation in color between individuals in a similar area or on a single individual, we need to investigate the reasons behind it.
A new article published in the Journal of Archaeological Science by Argáez et al. (2011) discusses the appearance of black pigmentation on skeletal remains from Mexico. The authors ascribe the coloring to a potential number of substances including manganese oxide, graphite, asphalt or bitumen, all of which create a black color on bone. The authors examined two populations from Mexico that had evidence of black coloration: Tlatelolco, a postclassical site from the 14th to 16th centuries CE and Tlapacoya, a preclassical site from the 10th to 8th centuried BCE. Three samples were taken from the first site and only one from the second. A small portion of the colored bone was removed from the skeleton, ground up, and was submitted to X-ray Fluo- rescence, X-ray Diffraction and Scanning Electron Microscopy. These methods revealed that the black substance on the boens could be attributed to bitumen, a black organic substance that is also found on the insides of shrouds from Albanian archaeological sites. Given the location of the coloring on the joints and knowledge of the region’s history, Argáez et al. (2011) argue that it was likely the coloring was accidental and was imparted during a dismembering process prior to burial. The bitumen may have been part of a hot substance, hot because the bone was thermally altered, that was used to ease in the dismemberment process by being a lubricant for tools.
A number of remains around the world have been found with a reddish pigmentation. The primary cause of red and yellow pigmentation is from ocher, a clay-like soil that when combined with water can make a non-toxic oil like paint. When found at burial sites it is primarily assumed that the deceased individual’s skin was covered in red ochre as part of the funerary rituals. When the flesh decayed, the coloration was transferred to the bones. Wreschner (1980) traced the early evolution of man and the use of red ochre, and found it was a reoccurring symbol in early burials. Red ochre burials were first apparent at Neandertal sites like Quafza and Lagar Velho.With the rise of early modern humans there was an increase in its use. In Mesolithic groups in Europe, over half of the burials that have been recovered have red ochre staining. In the Natufian culture in the Mediterranean, individuals were buried with dentalium head bands, or with red ochre, or with both.
Finding green stains is actual quite common in a number of historical and social contexts. Green stains occur when bones come into contact with copper or bronze that has begun to degrade. A study done by Hopkinson, Yeats and Scott (2008) look at the presence of green staining occurring on jaws in Medieval and Post-Medieval burials in Spain. Major stains were found on 18 of the 208 individuals recovered from a cemetery. The stains were only found at the mouth of the individuals and for some was so intense that the entire jaw was green including the teeth. The reason for this localized staining is due to the practice of placing a coin into the mouth of the deceased. This practices dates back to classical Greek mythology, where the dead were given money in order to pay the ferryman to take them across the river Styx. Although the rise of Christianity and Catholicism sought to break this tradition, it is still documented in art and literature. This staining shows that the act of ‘paying the ferryman’ continued even until the late Medieval period.
Argáez, C., Batta, E., Mansilla, J., Pijoan, C., & Bosch, P. (2011). The origin of black pigmentation in a sample of Mexican prehispanic human bones Journal of Archaeological Science, 38 (11), 2979-2988 DOI: 10.1016/j.jas.2011.06.014
Wreschner, E. (1980). Red Ochre and Human Evolution: A Case for Discussion Current Anthropology, 21 (5) DOI: 10.1086/202541
Kimberly A. Hopkinson, Sarah M. Yeats, and G. Richard Scott (2008). For Whom the Coin Tolls: Green Stained Teeth and Jaws In Medieval and Post-Medieval Spanish Burials Dental Anthropology, 21 (1), 12-17