Control crystal

Control crystals are crystals used for a variety of technology, including Ancient and Goa'uld (who presumably stole it from the former).

Ancient control crystals are small clear crystals. They are found in a variety of technology, including Puddle Jumpers and Dial Home Devices. DHDs have control crystals which contain information on which planets to the Stargate can link to, and where not to link to. They also send out new locations on the DHD's information update system. The Atlantis Stargate is the only one which can achieve an extragalactic wormhole, via a special control crystal.

Control crystals are also extensively used for Goa'uld technology. Long cylinders which contain informationa nd data storage, they are required to access and power a great deal of their technology, including the hyperdrives and weapons on Ha'taks. They are also used to store information on research that has been conducted.