Chisels, chisels, everywhere, but what is the right chisel for you? Straight up, when using a chisel for splitting and cracking rocks, safety must be your first concern. Don’t be trying to use a common wood chisel (designed of course, for wood) or a cold chisel (designed for electrical and metal work) on rocks. It’ll only end in failure, plus you’ll be embarrassing geologists, mineral collectors and palaeontologists everywhere! Don’t forget your eye protection either – critical any time that you are using striking tools.
The best chisels are ones designed specifically for rock work. Ideally, that chisel will be made from high-tensile steel and sharpened at an angle best designed for splitting rocks. There are a quite a few different types of rock chisels out there, but I definitely recommend the brand that is synonymous with rock splitting- Estwing. They’ve been making quality hand tools since 1922 and have most certainly got the design right by now. In addition to rock chisels, they are also specialist in other great tools for the Earth and Archaeological science, including things like rock hammers.
Depending on your work, there are a few different types of chisels to go for. The wide flat-ended chisels are designed for splitting layers sedimentary rock. The narrower chisels are best for heavy duty work. The pointed chisels are ideal for mineral collectors and rock hounds.
It is tempting to use the standard rock hammer for driving your chisels. If you’re careful, then you can use them quite usefully. But be aware, the rock hammer is not really designed for chisel work; the problem being that you are driving such a robust tool using such a relatively small striking head. The face of even the largest rock hammers might measure only 20 mm x 20 mm at best. When you consider that the standard chisel might have a strike face of comparable size, or even greater, then you’ll realise that a rock hammer is not the ideal tool for the job. It is far safer to use a striking tool that has a wider hitting face, such as a crack or drilling hammer, to drive your chisel.