I found an old piece of wood (at least 15 years) that I thought was walnut. It wasn't. It had a much deeper color and when I started turning it, I discovered it was VERY brittle. It kept tearing out as it got smaller.  If you look below the turned piece you'll see what is left of the piece. I used my sharpest tools and tried different speeds, didn't help. I quit as you see it, may not use it. Maybe it is Coco Bolo or some other exotic. 

 That brings up a question. Are there woods that don't turn well?

Edited November 23, 20205 yr by Ron Altier

It sure does look like walnut! Did it smell like walnut? I agree about the possibility of an exotic wood but but I don’t have a lot of experience with them 

 No, it did not smell like Walnut. Sure didn't turn like it either, very hard.

Looks like English Walnut or Claro Walnut. There are several woods that don't turn well such as Royal Paulina or Chinese Chestnut. I do not know of a DOMESTIC HARDWOOD i WOULD PUT IN THAT CATEGORY.

I am pretty sure it isn't domestic.  I bought this wood in Ohio at a huge Amish lumber company. They had a huge inventory of all kinds of woods. When I packed to move to CO, this piece got somehow lost. It could easily be one that Gerald described. Whatever it is.......it sure don't turn well.