You can finish extremely hard stone with Phenol Points, especially fire agate free-forms and jade carvings. Phenol Points are ideal for shaping and polishing of ruby, sapphire and garnet. Tools must be charged with diamond compound. The more the tool is used, the more the diamond becomes embeded in the point. Use any grit combination but 325, 1200 and 50000 will do a good job in most cases.
Is is important to use a separate Phenol Point for each grit. Always avoid cross contamination between different grits of diamond! It is important to wash the stone and your hands thoroughly between each polishing sequence.
Use a silicon based diamond lubricant and not water to provide lubrication for the Phenol Points. The Phenol Points are most effective when run at approximately 500 RPM with a micro motor or flexible shaft grinder. They all come with a 3.17mm (1/8" shaft).