Fig 7. Image of section 2–3 of the Phillips’ Core from Stone 58 at Stonehenge.

The right-hand end of the core segment represents a natural fracture in the original sarsen, with the thin band of iron hydroxide staining running diagonally from ~40 to ~50 mm mirroring the fracture surface. The left-hand end of the core represents a break developed either during or after drilling. The grey diagonal band running from ~10 to ~0 mm is residual metal from the diamond saw blade smeared onto the surface of the sarsen during cutting. This image is reproduced under a CC BY 4.0 license, with permission from British Geological Survey, original copyright (2019).