How do you find funeral details from bones?

Here, we look at how osteologists use the cremated bone fragments to reconstruct the details of the funeral, particularly the funeral pyre.

When bone is subject to extreme heat it undergoes colour changes that are visible to the naked eye. Research has established that bones will pass through a spectrum of colour changes caused by the sequential combustion of organic and inorganic components and depending on oxygen availability.

The colour changes

When heated, bone will first change from its normal ivory colour to brown, followed by black. This is referred to as ‘charring’ and is caused by the combustion of carbon and collagen in the bone. After this stage, the bone takes on a grey colouration which is caused by the polarisation of organic compounds. Once the bone’s organic material has burned away and the calcium has fused, it turns white. This sequence of colour change is always the same but it’s important to bear in mind that bones may also be stained by substances in the burial environment.

You can see the different colours in the image below. (These are actually animal bones but they react to heat in the same way as human bone.)

Photos of animal bone subjected to different temperatures, used as a colour reference ©Emily Carroll

Experts use this ‘macroscopic’ colour change to work out the burning intensity of the funeral pyre which can, in turn, tell us about cremation technology in the past. Cremation was probably more expensive than inhumation because of the cost of the wood; the price of wood would also have varied depending on how well it burnt. Larger pyres that achieved higher temperatures and required more maintenance indicated wealth and status and therefore the grandeur, size and events of that person’s final right of passage