The object touched radiates a magical field out to 20 feet that disjoins light. Complete darkness is unaffected. Light below the level of a light spell is reduced to complete darkness. Full daylight is reduced to the level of a light spell. Other areas equal to or greater than light in brightness are made dark enough so that normal sight is rendered useless, but not dark enough that darkvision kicks in (low-light vision functions normally).
Material component: A stone colored half white and half black.