This ten pound melon-sized rough ovoid of smoky quartz swirls and billows like actual smoke if you stare into it long enough. On command it creates a fog cloud with a radius of 60 feet centered on itself. Anyone touching the Fog Gem can see through the fog it generates. It doesn't require concentration to maintain, and it can be dispersed by the creator as a free action. The fog also immediately disperses if the creator stops touching the Fog Gem. The fog persists for up to 3 hours per day, regardless of how many times the cloud is created or destroyed.
When mounted onto a building or vehicle, the radius of the fog becomes 120 feet. Anyone within the building or vehicle can see through the fog it generates.
Originally commissioned by Old Captain Pete on a whim while fencing magic items, Captain Oya Stormqueen finally paid off the order and collected it for use aboard her ship The Grey Rover. Thea Willowstaff created the Fog Gem, but that was years ago, and she has only a vague notion of how she did it.