Data Crystals are crystals used by the Goa'uld and possibly Ancients to store information. One of these Crystals was used by the Goa'uld Thanos on the planet Langara. On this Crystal was the information about Naquadria. The Crystal was stolen by Anubis to try to reactivate his superweapon. It is unknown what happened to this Crystal. (SG1: "Homecoming")