Re: Mohs scale of hardness can kick the bucket.
alv...@example.com
> Ed wrote: <snip>
>> "MOHS' OR WERNER'S HARDNESS SCALE: WHO SHOULD GET THE CREDIT?
>> http://gsa.confex.com/gsa/2003AM/finalprogram/abstract_60785.htm
>
> Let the usage by metal users go and stop using Mohs Scale.
> It wasn't a metal scale in the first place.
> http://en.wikipedia.org/wiki/Mohs_scale_of_mineral_hardness
Notice the line where it says a file is 6.5 but the table just
below it says steel can be "8". Off hand, a file is the hardest
piece of steel that is "common". ~67hrc from my testing.
The table looks right to me in the area around glass and quartz
since some of my heat and cold treated knife blades can scratch
glass. ~66hrc (1095, 50100-B and even 8670-M)
http://en.wikipedia.org/wiki/Novaculite
Is there anything in an "Arkansas stone" (Novaculite) that's harder
than quartz crystals?
> http://en.wikipedia.org/wiki/Friedrich_Mohs
> Notice the subject that Friedrich had when he invented the scale.
> Martin H. Eastburn
Alvin in AZ
the wharf rat
>In sci.engr.metallurgy Martin H. Eastburn wrote:
>
>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...
Martin H. Eastburn
natural ones collected and shaped for the shop.
A extremely fine grain metamorphic rock typically with brown bands or cast.
The color indicates another material is mixed in the quartz. Perhaps topaz
or diamond. Arkansas is host to diamond fields. My bet is on other minerals
mixing in as in the painted desert and being of fine nature.
Might be chrome oxides as well.
I'll look in my Geo books more for this topic - rather - oh - a book!
Mineral facts and problems : Dept of the Interior Bulletin 630 Bureau of Mines:
"Sandstones are composed of quartz grains cemented with calcium carbonate, iron
oxide, clay, feldspar, or silica."
Knowing Arkansas a little - Aluminum is possible and the oxides are tough.
Martin
Martin H. Eastburn
@ home at Lions' Lair with our computer lionslair at consolidated dot net
TSRA, Endowed; NRA LOH & Patron Member, Golden Eagle, Patriot's Medal.
NRA Second Amendment Task Force Charter Founder
IHMSA and NRA Metallic Silhouette maker & member.
http://lufkinced.com/
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Timberwoof
> In sci.engr.metallurgy Martin H. Eastburn wrote:
> > Ed wrote: <snip>
> >> "MOHS' OR WERNER'S HARDNESS SCALE: WHO SHOULD GET THE CREDIT?
> >> http://gsa.confex.com/gsa/2003AM/finalprogram/abstract_60785.htm
> >
> > Let the usage by metal users go and stop using Mohs Scale.
> > It wasn't a metal scale in the first place.
Why is this thread titled "kicks the bucket"?
Given that it's about rocks, shouldn't it be "bites the dust"?
--
Timberwoof <me at timberwoof dot com> http://www.timberwoof.com
"When you post sewage, don't blame others for
emptying chamber pots in your direction." ‹Chris L.
meta...@hotmail.com
Alvin:
If you look around on Google you will find reference to a book called
“Industrial Minerals & Rocks: Commodities, Markets, and Uses”, 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:
“Natural abrasive stones are made from a wide variety of materials
including sandstone, novaculite…The 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.’
It doesn’t specifically mention garnet earlier in a discussion of
novaculite where it notes that material is primarily quartz.
Pittsburgh Pete
Martin H. Eastburn
since there are better scales.
Still used with stones.
Martin
Martin H. Eastburn
@ home at Lions' Lair with our computer lionslair at consolidated dot net
TSRA, Endowed; NRA LOH & Patron Member, Golden Eagle, Patriot's Medal.
NRA Second Amendment Task Force Charter Founder
IHMSA and NRA Metallic Silhouette maker & member.
http://lufkinced.com/
Timberwoof wrote:
> In article <g0i79k$d8r$1...@reader2.panix.com>, alv...@Example.com wrote:
>
>> In sci.engr.metallurgy Martin H. Eastburn wrote:
>>> Ed wrote: <snip>
>>>> "MOHS' OR WERNER'S HARDNESS SCALE: WHO SHOULD GET THE CREDIT?
>>>> http://gsa.confex.com/gsa/2003AM/finalprogram/abstract_60785.htm
>>> Let the usage by metal users go and stop using Mohs Scale.
>>> It wasn't a metal scale in the first place.
>
>
> Why is this thread titled "kicks the bucket"?
>
> Given that it's about rocks, shouldn't it be "bites the dust"?
>