In the wild, having a knife can mean the difference between life and death. A knife can help you cut branches to create a shelter and slice up kindling for a fire. It can dispatch and prepare animals and plants for food or defend you against predators. You can also strike a stone against the blade to get sparks for a fire. You may not have a knife with you if you get lost in the woods, but don't worry. You can make a knife from items in the wilderness. It may take a bit of time, but it should be the first thing you do in an emergency situation.
Items you will need
Flaky, thin stone
Hard, rough stone
Find a thin, flaky stone like slate or flint. These stones shear into thin, sharp pieces naturally and make good knives. Look for stones with glassy surfaces; rivers should yield some suitable palm-sized pieces.
Choose a palm-sized, round stone that looks hard and rough. This second stone should be fairly solid so that it doesn't break or shatter when you strike it against the first stone.
Hold your thin, flaky stone firmly in your non-dominant hand, cupping it with your thumb pointed down and away from you. Hold the second stone firmly in your dominant hand with the heel of your hand pointed toward the ground.
Strike the hard, rough stone against the edge of the flaky stone at a 45 degree angle. This should chip away a bit of the edge and leave a sharp place behind. Continue chipping your flaky stone this way all the way around the top 2/3 of the stone.
Create a handle for your knife by rubbing the last 1/3 of the edge of your flaky stone against the rough stone to dull the edge. This gives you a place to grip the knife without cutting yourself.