David Weaver
A very hard (harder than novaculite in feel and musical note when tapped) slow natural stone from the west and southwest. I've had good luck with two types of true jasper - biggs and owyhee.

You want nothing to do with these unless they're a large uniform slab that's already polished to a flat gloss surface - they'll be about 1/4th inch thick and you'll need to glue them to something stable.

No clue what the price is now, but large slabs in jasper are something like 6x3. There are a lot of small pieces intended to be cut into jewelry.

Biggs - usually white and iron oxide red
owyhee - add green to the above

David Barnett told me long ago, if you get these, you'll have better luck finding a piece with less color variation. I see this as a two-fold benefit (i've had maybe 8 slices of this stuff) - first, a plain looking stone will be very even and not have any weird spots, and second, you'll be able to actually see if there are little voids or cracks.

Price for each of these when I got them was about $10.

Very slow, too slow really to be practical, but a good burr chaser. I didn't scratch the top of this stone, and i used it with a thin film of honing oil. If this stone is scratched, it is fine cutting but extremely aggressive and will raise a tiny burr.