You will have better luck with a blade embedded with silicon carbide. Iron meteorites are very hard on diamond blades of conventional lapidary saws. Some cutters use carbide blades. The best bet for cutting is probably to leave it to the professionals. It usually takes one to five minutes to properly etch a surface.
Etching is a art that requires much experimenting and experience.
Rocks From Space has an appendix that gives detailed instructions. I suggest that you use this or some other reference. But be prepared to takes some time to learn. Once you are satisfied with the etching immerse the meteorite in distilled water for a few minutes. The purpose of this step is to neutralize and dilute the nitric acid.