D&Dtools1

You prepare a magical matrix that allows you to store one of your spells and use it later as a free action.
In the round after you cast Simbul's spell matrix, you may cast one spell of up to 3rd level to be stored in it.
The matrix closes after 1 round, whether or not you have stored a spell in it.
Only a spell that can be altered by the Quicken Spell feat can be placed in the matrix, and any spell stored there is treated as a prepared spell.
Casting Simbul's spell matrix deals 1d6 points of damage to you, and this damage cannot be healed by any means while the matrix exists.
While the matrix is active, you can cast the spell stored in it as a free action.
Once cast from the matrix, the spell is gone.
A dispel magic spell that successfully dispels the matrix also dispels the spell held inside it.
If you are affected by an antimagic field, the duration of the matrix is interrupted, but the spell does not activate.
The matrix becomes active again when you emerge from the antimagic field.
If you die while the spell is still held in the matrix, both the spell and the matrix dissipate harmlessly.
Focus: A piece of amber with a minimum value of 500 gp.