Thread: What is the Sp Gr of Your Best Arkansas Stone

Each mineral has its own density. That density does not vary according to the size of the sample. S. G. is just another way of identifying, grading and showing the difference between different minerals. You may as well ask 'Why Rockwell hardness' or 'why MOHS hardness' but knowing you Tom, it would probably be 'why aren't orange apples orapples?'...

Regards,
Neil

I take a razor and put it on a stone. It either works well or it doesn't, some are better than others. Like the old watchmaker told me when I asked him if 'this' is a good watch. Does it keep good time, he said, if it keeps good time it is a good watch.

Ah, but then there are watchmakers and there are watchmakers, Jimmy!

My dads friend took a watch into a jewellers near where they were working. It had a fault and wouldn't wind.

My dads friend said 'can you have a look at this watch, mate' and gave it to the jeweller.

The jeweller, being a bit of a wiseacre, said 'Very nice' and handed it back.

Not to be outdone, dad and his friend turned round and walked out the shop. They never went back.

And the moral of this story is, er, is there one? Tom will know.

Regards,
Neil

Originally Posted by sharptonn

Specific gravity. Hmmmmmm. Why? If it WERE accurately determined, what does that tell you? Compared to what??

It's a decent indicator of the fineness of a novaculite stone when compared to another novaculite stone if they're in the same shape (e.g., lapped fresh with a diamond hone or right off of a factory lap).

Probably not too useful for comparing different types of stones.

The grade sheet from the government is probably the reason for interest in it.

I just looked at dan's schedule. It provides way too much leeway into what's hard and what's soft. There's a large difference between 2.3 SG stones and 2.5 and a large difference between 2.5 and 2.7. Less difference between 2.7 and beyond in my experience.

The least dense stone I've tested is what dan's calls their washita (which is not similar to a pike washita), which in the version that I got is 2 SG almost exactly. It's also a fairly fragile stone, and mine arrived with a corner cracked off in the box. It's not really a relevant stone for razoring, anyway.

Originally Posted by Neil Miller

And the moral of this story is, er, is there one? Tom will know.

Regards,
Neil

Certainly, Mr. Miller!

Originally Posted by JimmyHAD

I take a razor and put it on a stone. It either works well or it doesn't.

This is the best test, above and beyond SG (I guess the SG does, though, at least confirm that you're getting what you've paid for).

Originally Posted by sharptonn

Certainly, Mr. Miller!

I knew there was a point! Just like the moral of your story, I have been ?@2$*! for a very long time indeed.

Regards,
Neil

Originally Posted by DaveW

2.84 is definitely way into the density range for the true hard/black/translucents and has plenty of potential. hard arks are so variable that from that point, it really comes down to how you condition the stone and how you use it and maintain it.

Quoting my own post since rereading it, it could be misleading. They are variable in the 2.7+ SG range (and maybe below) but "very variable" for novaculites would be nothing compared to the variability of a coticule. The high density stones are consistently good and in a fairly narrow range, just meant to suggest that a stone at 2.75 SG may not necessarily be distinguished from one 2.85 SG when used. I would've guessed the dans black that I have and the dans trans were my two most dense stones if I had to guess just based on what the razor is like coming off of them, but they are, IIRC, 2.7 SG or so, and my densest is the dark trans that Natural whetstone sells as "black trans".

Used in a vacuum, they are similar enough that without comparing the two together, I'd never feel short of options if I had one or the other but not both.

Originally Posted by sharptonn

Certainly, Mr. Miller!

But which one did the gravity test… and on what?

Originally Posted by Euclid440

But which one did the gravity test… and on what?

Well....it is a proven fact that gravity sucks!