Lapis philosphorum: the gold and blue of the virgin’s cowl descend. To the left there is a busyness of rushes and to the right these open out to reveal a pool of water. There is no balance in this philosophical discourse, rather a rock is weighed by the deformation of metal.
This is a piece created, I think, specifically for the RA in 2013, and is striking for the heavy gold leaf overlaying blue at the top and the sculpture projecting in front of the flat image.