Grinding stone?

Hey does anyone out there know what type of stone would be good to make a grinding stone/metate?

I am teaching myself how to grind wild grass seeds to flour, and I have a good mano, of basalt, sort of rough and very hard. I found a nice flat stone I was going to use as the lower grinding slab, but when I tested it, it was too soft-- shale or something, producing a fine powder that I would not like to eat. Back to the search.

You could try using a different type of stone to grind, something softer (but not so soft that it will also turn to powder).

But if you have your heart set on your current mano, try a granite slab. You may not be able to find it naturally but it’s durable enough to last a long time if you treat it right.

I’ll get out thee and look around. Granite night be a good idea, a nice river-worn boulder or something. The mano is nice because it has “tooth” to help grind.