Should I lap a natural stone?

I have one of these chinese stones I got at SRD
Vintage Blades LLC::Sharpening Stones::Waterstones::Natural Finishing Stone - 12,000 Grit

Should I lap it periodically with my Norton lapping stone?

I would say yes, but to be sure, test it yourself. Draw a grid on the hone with pencil, take it to the Norton (or sandpaper on a *very* flat surface) and see how evenly it removes the pencil mark. If it all disappears evenly, then you're good. If it doesn't then continue lapping until it does. You'll need to re-draw the grid from time to time as it is worn/washed away.

I used a Norton stone on my PHIG for a while and it worked OK. A DMT plate works even better, but at extra cost. The Norton will do the trick.

Thanks man. I am going to get a DMT one of these days. I want to invest in a 16k first and maybe a couple of chorosa or naniwa stones as well. I just didn't know if the synthetic against the natural would screw anything up.