It can't be petrified unless it's been without air to make it rot for millions of years. it would also most likely have to be buried to accomplish that. I have cut a hickory that had been dead a while and it would dull the chain quite fequently.
My guess is that this guy has some wood (mahogany) that has been stored in log form for 20 years for whatever reason. If so it may be like our old hedge posts in the midwest where they are so hard you have to drill a hole in the post to drive a nail in them.
If it was that bad I would look into some of the carbide coated chain. It is moderately expensive but should last through the wood he has to cut. From what I understand it doesn't cut as fast but does cut longer in abrasive conditions. Wouldn't your axe get dull too?
I have cut honeylocust that had been girdled and knocked down along a field on one of the river bottoms around here. It had been flooded so there was a lot of sand in the bark. About 5 cuts through an 18-20" log and the goody was out of the sharpening on round chisel chain. Another 10 cuts and the chain was done. The wood does seem to burn well. (in the stove as we speak)
Don.
Soooo how did he have it if it couldn't be cut???? Was is still standing? Did he cut it with a wet saw?:biggrinbounce2:
I have some Hophornbeam (some call it Ironwood) around here. Very very hard, but it can be cut. The only one I have worked with that will dull anything fast is Ipe from Brazil.
Heapem hard wood. Burn long. Much heat.
I trade you for some whiskey and beads and rifles.
Can't be cut with a saw but can be notched with an ax? Puuhhhleeeze.
Harry K