On my desk, next to my laptop, a small piece of lapis lazuli. My eye is captured by the intense blue from its most important component, the mineral lazurite. The stone also contains white calcite specks and some metallic glistering from its pyrite elements. Looking at the play of colors, feeling the weight and the surface of the rocky material, I am reminded of Marguerite Yourcenar’s words at the end of her introduction to Caillois’s The Writing of Stones when she invokes stones as force fields “at the intersection of countless lines crossing one another” (Yourcenar xix). And I wonder, what are the force fields and intersecting lines “receding to infinity” contained in this small piece of earthly material? How has this ultramarine blue become “the most perfect of all colors” (Cennini 36), as described by Cennini in his famous The Craftman’s Handbook of the late Middle Ages? How has lapis lazuli traveled in the world, as an aesthetic object, as a perfect pigment for the most beautiful blue, but also been implicated in economic and political forces? What kind of “geomediations” traverse this deep blue stone?