The block of bloodstone was cut in two by the local stone shop since it was too big for my saw-vise. The guys there are fascinated with these big rocks so are eager to do my bigger than average slicing. They gave me a funny look when I went to pick up the pieces. They were not used to cutting such tough material and were amazed at how slowly this monster saw took to cut (the India bloodstone) with a 36" blade for cutting counter top slabs. From the two pieces of bloodstone, I got two spheres. They were rough ground with diamond cups. My machine is a Covington 3-head sphere machine, now 4 years old and 350 plus spheres cut. My protocol for most agates and very silicified jasper continues as follows: Next they went to 3 inch steel plumbing couplings for better rounding and #90 carborundum grit. It took several hours, maybe 6 each. Next they went to 2.5 inch brazed cups with 220 diamond-filled rods from Wes Lingerfeld (C & G Gemcrafts.), about another 2 hours. Then onto PVC plumbing fittings with 220, 400, 600 and then 1,200 diamond grit in lithium grease, about one hour each. Added lubricant is WD-40 alternating with petroleum based cutting oil. I think Pella made by Shell Oil would work fine. Finally on to #8 canvas-covered PVC fitting and Cerium Oxide about 1-2 hours. As a last step, the polished spheres are soaked in Oxalic Acid overnight to remove any Cerium Oxide caught in tiny defects. For most other stones, I use diamond grit from 220 to 100,000 in 8 steps, but then again, I cut unusual material most of the time. Obsidian, petrified wood and beryl are worked nearly the same way, but with some very important differences.