Psychometry was the ability to sense the impression of past events, thoughts or emotions: the stronger the emotion, the clearer the psychic impression. Any object was imprinted with its history, particularly with strong emotions, (TV: The Rings of Akhaten) so that simply by touching it, a person could divine an object's past, seen in images and memories. (TV: Planet of the Spiders) According to Tarron, the science of psychometry allowed expects to "divine" the characteristics of the last person who'd been in contact with an object, such as a murder weapon. Barbara Wright described this as "an improvement on fingerprints." (TV: "Sentence of Death")
The court of Millenius performed psychometric tests on the weapon that killed Ayden to find his killer. They believed it was Ian Chesterton. (TV: "Sentence of Death")
Professor Herbert Clegg demonstrated his psychic powers for the Third Doctor by using psychometry (called psycholotry by the Doctor) on the sonic screwdriver and a crystal taken from Metebelis III. In the former instance he saw Drashigs. With the latter, the images of the Eight Legs frightened Clegg so much that he died of heart failure. He showed the Doctor these images through use of an Image Reproduction Integrating System. (TV: Planet of the Spiders)
Silverman was a psychometrist. Bart Addison took Mykloz to Silverman to find out who he was by the objects in his pocket. Although the objects seemed to indicate that Mykloz was the Seventh Doctor, Addison deduced that he was not. (PROSE: Playback)
Most of the commerce on Tiaanamat was done using psychometric objects. For example, Clara bought a moped from Dor'een using a ring from her mother, since she had strong memories of her. Psychometric offerings were also given to the Old God during the Festival of Offerings. (TV: The Rings of Akhaten)