A short cylinder of marble laid on its side against the wall, open at both ends, so the warm light escapes as two clean beams, one up and one down, while the stone itself glows in between. The marble is heavily figured, cream broken by charcoal veining, and backlighting turns those veins into something closer to weather than pattern. Nine centimetres across: small enough to run several up a staircase, substantial enough that one beside a basin is not apologising for itself.
