X-rays are particularly useful for studying metal objects, where rust and corrosion from being buried can hide decoration, or even make it difficult to see the original shape of an object.
X-rays are sometimes used to examine large or fragile objects, such as mummies or cremation urns, before they are excavated.
X-rays are also used for studying human remains.
An x-ray of a witches' bottle, showing the pins inside the neck. These were used as magic charms to keep witches away during the 16th and 17th century. The bottles were filled with pins, human hair and nail clippings and often also with urine, and then buried under floors or thresholds © York Archaeological Trust