I am trying to find information or a technique to drill 1/2 - 3/4" holes through stones - The stones are approx. 8-10" in diameter and 4-8" thick.
Use a rotary hammer drill. Take one of these rocks to your local tool rental center. They'll get you fixed up with the right equipment
Hilti DD EC-1 core drill. Figure out a way to clamp or hold the stones in place. Call around and see if any rental places have this particular Hilti. It is the smallest core drill made by Hilti, and the only one capable of drilling a 1/2" hole. I think a rotorhammer will crack the stones. A core dril is the way to go. Here is a link to Hilti: