When limestone gets even more squashed, it can turn into travertine or marble. Limestone is also the main way you get lime, which is one of the things you make cement out of. To get lime, you have to burn limestone in lime kilns, and then what is left is lime. In the Middle Ages, people burned most of the statues of ancient Greece and Rome to turn them into lime.
Far as I am aware, CBD oil is not legal in Texas. It is legal for medical use in only Utah, Alabama, Kentucky, Wisconsin, Mississippi, Tennessee, North and South Carolina, Iowa, Florida, Georgia, New York, and Missouri.
One of the keys to ensuring that the CBD oil one is consuming lacks THC (or harmful contaminants or pesticides) is to obtain it from a legal, regulated source. The black market bingo practiced by many patients often results in obtaining products that are low in quality, contaminated, or not what they claim to be.