Afterimage

Afterimage was a term used by the Eleventh Doctor to describe what remained of the Alliance following Total Event Collapse in 102 AD.

Time War
Through the extrapolations of the Matrix, the Time War-era Time Lords foresaw the Total Collapse Event Incident from the Doctor's personal future, which was recorded in the Dalek Combat Training Manual. Observing the effect total event collapse had on the Daleks, reducing them to stone afterimages, Time Lord Weapons Architects explored the possibilities of exploiting Localised Event-Collapse Time Fields as a means of petrifying whole fleets of Daleks. (PROSE: Dalek Combat Training Manual)

Total Event Collapse
As discovered by himself and Rory Williams in the Underhenge, several members of the Alliance, including a pair of Daleks, a Cyberman and an Roman Auton, had been reduced to stone fossils. As the Doctor explained to Rory: (TV: The Big Bang) "History has collapsed. Whole races have been deleted from existence. These are just like afterimages. Echoes. Fossils in time. The footprints of the never-were."

- The Eleventh Doctor

The Pandorica held atoms from the original universe, taken before the cracks erased events, which could sustain life. In 1996, Light from the Pandorica restored one of the Daleks, albeit with limited power. This stone Dalek shot the Doctor, severely wounding the Time Lord without killing him but depleted its energy reserves nonetheless. It was confronted by River Song, who threatened to kill it by shooting its eyestalk with an Alpha Meson gun. Initially, it did not believe that River would destroy it, thinking that as one of the Doctor's companions, she would show mercy. River told it to look her up in its data banks. After doing so, it began to plead for mercy, shaking in terror. Later, when Amy and Rory asked where it was, she stated, "It died."

When the Doctor rebooted the universe and timeline, the stone afterimages, along with all things that had been erased from history, were restored to their original form and place in space and time. (TV: The Big Bang)

Merchandise
Action figures based on the Stone Dalek, Cyberman and Roman Auton were released by Character Options.