callmerob
starting to spend too much on rocks
I really like a dirt road
Member since September 2019
Posts: 131
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Post by callmerob on Oct 9, 2019 0:40:55 GMT -5
It's neither linear nor logarithmic. It's truly arbitrary. For instance, Sapphire is the definition of 9. Diamond defines 10 and is something like 150 times harder. Mohs just took common stones and made a scale. As for jasper and agate, some say it's the same material as quartz so they say it's a 7 (quartz defines 7). This is a mistake. Diamond and graphite are the same material, carbon. But very different on the world of hardness. Agate will not scratch quartz, but quartz will scratch agate. I learn something every single time I'm on this site. Mohs' scale is arbitrary, but still gives useful comparative numbers. Ok, that makes sense. I have a casual familiarity with metallurgical hardness indentation tests where the equipment measures in lbs/in^2, and the results are ultimately talked about in Rockwell B & C scales which are dimensionless but still comparative and useful. Thanks again for your reply.
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NevadaBill
fully equipped rock polisher
Member since January 2019
Posts: 1,332
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Post by NevadaBill on Oct 27, 2019 13:58:30 GMT -5
What a neat report! I wish that I had time to read this before passing through Goldfield only the other day. Thank you for sharing, and great looking rocks!
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RWA3006
Cave Dweller
Member since March 2009
Posts: 4,125
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Post by RWA3006 on Oct 27, 2019 17:25:43 GMT -5
Goldfield is a hoot, so is Tonapah. We went there three years ago and got a bunch of goodies at Gemfield. If you're ever there go tour the cemetery on the Northwest end of town and you can see cool old tombstones that say "Indian Molly" and "unknown man died eating library paste."
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