White-Point Star

A White Point Diamond was a diamond that was found only on the planet Gallifrey. The Time Lords whilst being Time-locked in the Last Great Time War sought a means to escape their imprisonment and thus their destruction. This led to Lord President Rassilon in using The Master as a means of escaping into the universe. However, whilst the link was present in his mind, there was no physical link which led to Rassilon sending a White Point Diamond through the time-lock which the Master as Harold Saxon recovered and used as a means of bringing both the Time Lords and Gallifrey into the universe once more. (DW: The End of Time)