Stone that's readily carvable includes slate, limestone, sandstone, and marble. Uncarvable or hard-to-work materials include roofing slates, cement, cast stone, granite, or ceramics.
Equipment is basically a chisel and a dummy mallet, http://www.tiranti.co.uk/ (near Gt Portland Street station) sell them, (plus goggles and steel-toecapped-boots).
The easel was built downstairs in the hackspace from some of the scrap timber plus a hinge and a couple of 10mm carriage bolts. It is living next to the stepladders.
- Lean easel securely against a wall
- Lay a crossbar, thicker than your stone, between the square washers and the easel
- Tighten the wingnuts
- Lay the stone on the crossbar
- Either clamp the stone directly to the easel, or clamp a piece of wood above the stone with clamps so that the stone is firmly held in place between that and the crossbar.