Do I need to remove clove stems before grinding? I have whole cloves and need to crush/grind them. Should I break the berry parts off the much-harder stem and just grind that, or is the whole thing meant to be used?

(I'm using a mortar and pestle, not a spice grinder, so non-mechanized manipulation may make a difference!)
One clove is "the berry part", as you describe it, and the "stem". Use the whole thing.