Extended Data Fig. 6 | Geometry of the toroidal shape. a, Scanning electron
micrograph of the anvil. b, Profile of the toroidal diamond tip measured by
interferometry. c, Scanning electron microscope image of the toroidal anvil
recovered after pressure release. The toroidal part of the anvil is intact. Ring
cracks are seen on the bevel of the anvil, at a diameter of about 150 μm.