Etheryst

An etheryst is a prism which has been imbued by magic to radiate a permanent effect within a region, object, or person. The arcana which etherysts harness is typically minor, though etherysts require a permanent link to the ether, and worries abound about how they might be altered to cause a dramatic flow of energy into the Material Plane. Such a flow would undoubtedly result in a devastating explosion of the Warp, which would potentially be unstoppable and world-shattering.
Etherysts are generators. Typically, in order to harness their energy and direct it into a specific form, they require additional materials. These materials tend to be such that they are magically active, such as redpowder or exaltium. In practice, exaltium is the most commonly-used director for an etheryst.
Examples of technologies which make use of etherysts include the Lightning Rail, which uses arcana to propel a train without a mechanical engine.