Search:

Well a steel file is about mohs 6.5. If there are a lot
of carbides it will be a lot harder. Carbides are hard....

Quartz at 7 will worry steel nicely. It is hard to find fine
grain quartz...

I doubt that a Jade hone is anything to aspire to.
A jade color hone perhaps.

Jade is a valuable material and a slab of jade that was free of
defects to the degree that it would make a good...