|Purpose||Negate effects of a crystal|
The Blocking Crystal has the power to block another crystal’s power. Piper was trying to figure out how to make the effect of the Blocking Crystal last longer. She also used it to reveal that Lark was Master Cyclonis.
The Blocking Crystal is several different shades of green and its shape is a mix between a octagon and a rectangle and has a metal cross around it and at the center of the cross is a classic shield symbol.