Soul Prisms

Soul Prisms are encountered in Ultima VII Part Two: Serpent Isle.

Description
The process to create them is thus:


 * First, ask Ducio to craft a Worm Gem by giving him the 3 worm hearts. You only need nine to make three of them.


 * After the gem is created, you must cast "Create Soul Prism", which was given by Torrissio. This turns the Worm Gem into an empty soul prism.

Beware! Soul prisms will not be able to hold a powerful spirit for long unless they are treated appropriately. For instance, in the case of the Banes of Chaos the Avatar must treat each prism with water from the Shrines of Chaos to be effective (Batlin skipped this part).

Trivia

 * A soul prism that captures the soul of a once-living warrior is called a living gem, which is what grants an automaton 'true life'.