When SHTF you will hopefully have prepped some supplies. If you, unfortunately, do not have some of the essentials, consider that a lot of your supplies can be crafted from natural resources. Tools and a weapon would be lifesavers in a survival situation. A knife will be an asset to have for multiple reasons. First for protection from threats such as predators or for self-defense. Hunting, Dressing your kills, crafting traps or snares. To cook with as well as creating a shelter or mending cloth or clothing. So if you happen to find yourself without the proper tool, do what our ancestors did, build with what the earth provides.This article is here to teach you how to craft a knife from a rock or stone. Think about it, spears and arrowheads all created from a rock. If they could do it so can you.
Finding the right rock: You will need to locate areas where rocks of good quality will be. Creeksides and creek beds tend to have tons of these types of materials. Look for ones of larger size with a flat or concave side. Test them to ensure these will make a good knife. Clank a rock on another, you want to hear a glass or ringing sound. Once you have that one picked out then you need to find a hammer rock or stone to shape the rock into a blade. This one should be medium sized with a somewhat round surface.
Breaking off your blade: set your blade rock on another larger flat rock or you can use your thigh if you are careful. Using your hammer hit the edge of your blade rock at an angle. Be sure to follow all the way through with the hit. You should end up with multiple chips that will be sharp on the edges so use caution at all times when crafting and using these. For a larger blade choose a larger chip. You can continue to chip until you have a piece you are satisfied with.
Some of the chips will be ready to use if they have a sharp edge to start with. Otherwise, you will want to refine the blade by softly hitting the ends to form a sharp point. The more time you spend on crafting your tool the better quality it will be. I would also recommend creating a handle with either a stick or even just some thick cloth or sting. Wrap the material around the end opposite of the tip. This will help with grip and help avoid injury to yourself, considering the rock will most likely have sharp edges on all sides. When cutting with your knife it may not be the sharpest knife that you can find in a store, so you will need to do multiple cutting motions. Always cut away from your body.
So try this process out, practice it. When the time comes you will be able to create something from nothing. Ages ago these were all the materials people had to use, and look at all the Amazon things they did with them. So invoke your primitive instincts and use what the world provides.