Re: Mohs scale of hardness can kick the bucket.

>Is there anything in an "Arkansas stone" (Novaculite) that's harder >than quartz crystals? >

AFAIK novaculite *is* a form of quartz, it's a sedimentary rock made of very fine quartz crystals...

Reply to
the wharf rat
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Alvin: If you look around on Google you will find reference to a book called =93Industrial Minerals & Rocks: Commodities, Markets, and Uses=94, 7th edition. If you look at the preview in Google Books you will find that on page

153 of the chapter on abrasives it notes that:

=93Natural abrasive stones are made from a wide variety of materials including sandstone, novaculite=85The superior cutting quality of some of these stones is due to the well-disseminated, fine-grained inclusions of garnet or other minerals of superior hardness.=92

It doesn=92t specifically mention garnet earlier in a discussion of novaculite where it notes that material is primarily quartz.

Pittsburgh Pete

Reply to
metalengr

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