This is coral that has been silicified over the ages,it ranges in color and quality from the minerals that are in the area.Most of the coral I use comes from West Central Fla.There are coral deposits in other south eastern states also.The points I'm holding are made from what we call pinhead coral and and has been silicified to the point that it is transparent.In it's purest state it can be knapped raw and makes a sharp edge. There are folks that make beautiful jewelry and cabs out of it. Hopes this gives you a better idea of the kind of coral that is knappable.
Roger