What is interesting is the use of marble with strong, deep veining and when did the use of such marble become common use.

We know that such marbles were in use for decoration in churches around the end of 1400. (Santa Maria dei Miracoli, Venezia 1489)

When you cut and divide a marble block and open the two slices as you open a book, you obtain a symmetrical image, like a Rorschach-blot used in psychiatry. Such occurring images in the church of Miracoli must have had a strong effect on members of the congregation when in moments of boredom their interest turned to the surrounding decorations. Suddenly they discovered images born from their fantasy that would fill them with emotions of different kinds. Some would see angels where others would see monsters and horrors, without knowing where the images came from, because the reality was just plain marble. These images would accompany the preacher’s threatening stories of heaven and hell and stimulate the conscience and imagination of poor sinners amongst the listeners. But the decorators went further. They cut the same marble block into four slices and opened the imagery like you open a folded letter. The horrors in the emerging double symmetry multiply as the fantasy develops. (Even more so had the stone used been the multicoloured onyx.)

Did the marbles inspire the artists at that time?

Did the marbles inspire the congregation in churches?

Were such marbles used deliberately to create more or less evident images and not only for pure decoration?