When embalmed, the weight of the body is reduced by more than 70 percent, but only liquid disappears, and thus different bodily minerals are greatly concentrated and seen more clearly.

The Greek historian Herodotus described the embalmment process step by step, but scientists still had unanswered questions, so in 1994, Long Island University professor Bob Brier performed an embalmment using ancient Egyptian methods to make a modern mummy, which answered some of the questions. For many years, scientists thought that the dark color was due to resin treatment and the long stay in the tomb. But Bob Brier’s mummy turned dark brown after only 35 days of dehydration, leading scientists to conclude that the change of color occurred in tandem with the falling body weight and was caused by a high concentration of iron.