<VV> Stainless valves lapping

[D. Monasterio]

    As part of a head change on the Rampside, I am using new stainless steel valves (my first ones) but, while lapping, noticed that the grinding compound does nothing on the valve seating area, only on the head seats. Are this valves harder than the grinding compound ? or... should I use an special compound (diamond) ? or... is it ok having the grind on the seats only as long as they seal ?
    Feel like a newbie...

    Daniel Monasterio