If you don't have a sharpening stone for your knife, remember that any sandstone will sharpen tools (a grey, clayey sandstone being the best). Quartz is good, though rare, and granite can also be used. Rub two pieces together until they are smooth. A double- faced stone with a rough and a smooth surface will be ideal and should be carried in the sheath pocket.
Use the rough surface first to remove burrs, then the smooth one to get a fine edge. The object is not to get the sharpest edge possible, but to get an edge that will last and not chip.
To sharpen the blade, hold the handle in the right hand. Use a clockwise circular motion and apply a steady pressure on the blade with the fingertips of the left hand as you push away. Keep the angle constant. Keep the stone wet. Rock particles on the blade will show the angle you are obtaining. Do not drag the blade towards you under pressure as this will produce burrs. Reduce the pressure for a finer edge. Work counterclockwise on the other side.