Final answer:
East Texas has little good knappable stone, but sandstones, red shales, and siltstones are three examples of such stone that can be found there.
Step-by-step explanation:
East Texas is known for having little good knappable stone. However, there are still a few examples of the type of stone that can be knapped or shaped by humans. Three examples of such stone in East Texas are sandstones, red shales, and siltstones. These rocks can be used to create tools or artifacts through the process of knapping.