Players can add a small jewelcrafting building to their garrison.  Currently, Blizzard has referred to this as the Jewelcrafting Shack in the UI shown at Blizzcon, but called it a Jewelcrafting Gallery, leading me to believe the names upgrade as you upgrade the buildings.

The Jewelcrafting building can be upgraded to level 3.

Followers with the jewelcrafting profession can go out in the world to collect jewelcrafting mats and find new jewelcrafting recipes.  It is unknown if followers would be gathering cut or uncut gems.