Deep Flame (Uncommon Wondrous Item) In truth this is a naturally occuring crystal, found in regions of the world that stand close to active gates to Fey dimensions. In light, it appears to be a glassy, cuboid or prismatic crystal of deep blue or black colour. Light plays over its surface with a strange labradorescence, and its shadow is oddly morphic, having no real relationship to the shape of the piece casting it.
In darkness, how the crystal appears depends on the one seeing it. Creatures without dark vision see nothing but the darkness. However, those with darkvision see that the crystal emanates bright light, the radius of this being a product of its size.
As a general rule, for every 1 inch diameter of crystal present, it emits bright light in a 2ft radius, and dim light for 1ft beyond.
This crystal is highly prized by many subterranean races for illuminating areas – usually for cosmetic effects, though others make use of them as signals, boundary markers, and in combination with certain other spells and effects, defensive items.