Using an impenetrable material like concrete, which allows no light to pass through it, can often be an interesting choice to use for a light fixture. Yet, by slicing the idea of a lamp in half, you get a playful lamp that functions just as if it was produced using a more forgiving material. Designer Troy Reugebrink did just that for Eindhoven-based label qoowl in his Crescent lamp.
With only 1/2 of the lamp solid, the light glows from the other side. Keep it close to a wall and the light bounces off of it creating a soft, ambient glow around the silhouette. If you need more light, turn the lamp towards you.
The shape of the Crescent lamp was 3D modeled in order to adjust the center of mass, allowing it to stand up properly.