markward
off to a rocking start
Member since December 2006
Posts: 23
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Post by markward on Dec 31, 2006 9:39:39 GMT -5
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Sabre52
Cave Dweller
Me and my gal, Rosie
Member since August 2005
Posts: 20,456
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Post by Sabre52 on Dec 31, 2006 10:39:42 GMT -5
Mark: First rock does look like it could be some sort of limestone, dolomite, marble or fine grained travertine but all of those are hardness 3 and above ( usually 3-4). Second picture is pretty blurry but not what I know as siltstone which has a hardness below 5 and is easily scratched by a knife blade. Mohs 9 would make it in the corundum hardness class which it does not look like. Maybe if it was a little less hard ( I don't know what you're using to determine hardness) it could be some sort of silicified sediment as it does show layers. Those can get up to about mohs 7 in hardness....mel
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markward
off to a rocking start
Member since December 2006
Posts: 23
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Post by markward on Dec 31, 2006 11:01:49 GMT -5
Hi Sabre, i have modified the listing regarding hardnesss as a carbide glass cutter did scratch this clearly, but using the steel file it put a very light scratch so have changed it to 7. Thanks once again for your expertise.
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markward
off to a rocking start
Member since December 2006
Posts: 23
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Post by markward on Dec 31, 2006 11:04:09 GMT -5
Forgot to mention that the Limestone can be scratched with a finger nail so no more than hardness of 2
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markward
off to a rocking start
Member since December 2006
Posts: 23
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Post by markward on Jan 2, 2007 16:14:15 GMT -5
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markward
off to a rocking start
Member since December 2006
Posts: 23
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Post by markward on Jan 5, 2007 19:36:25 GMT -5
Think i sussed out what the second rock is ; Ledgestone ?
The banding is only along the front and sides and not inside , inside looks similar to a dark sand/cement mixture
Obviously a stone which is manufactured to look pretty on outside only.
Guess i won't be polishing it now.
Common sense should have told me this in the first place and just goes to show that this hobby has a very large learning curve.
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markward
off to a rocking start
Member since December 2006
Posts: 23
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Post by markward on Jan 8, 2007 17:12:20 GMT -5
Still wondering about the first rock which was suggested to be Limestone. This rock is very similar to chalk and as soft as (which is limestone) but wouldn't this fizz when hydrochloric acid was placed onto it.
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Post by ladyt on Jan 9, 2007 18:24:13 GMT -5
Yes limestone will fizzle with acid placed on it. Maybe it's some kind of shale rock? With the layers and all, that's what I thought. Maybe take a small corner of one, grind it down to powder, than add the acid. If you weigh it before adding the acid and then again after the acid and after drying, you would be able to mathmatically calculate the % of sand to limestone. That might help in classifying it. Tonja
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markward
off to a rocking start
Member since December 2006
Posts: 23
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Post by markward on Jan 9, 2007 18:33:52 GMT -5
Many thanks Tonja Wii give it a go!
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jrtrio
has rocks in the head
With10 tumblers tumbling the sound is so delicious!Send me more of those little red fellas, please?
Member since February 2006
Posts: 535
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Post by jrtrio on Jan 10, 2007 13:39:54 GMT -5
Are you not polishing the stone because it is man made? That would be a mistake based just on the fact that it is man made. There are several stones that we tumble/polish that are man made and one of my favorites is, I believe it's called: Gold Sand, (at least I was told that it and the purple version of the same rock are both man made). A beautiful stone that is a deep dark rust color with gold flecks through out. I've also seen several stones/pieces tumbled/polished that were from broken up counter tops. So, if you aren't tumbling or polishing something that is "man made" you should re-think it. I feel if you see something that catches your fancy and you think that it will turn out beautifully no matter who made it, man, nature, valcano, God....then as Nike says..do it. I have some rock that I'm not sure who made it, called "Muggle Stone" (gee did man make it after the movie/books or before?) and one reason I'm a little anxious about tumbling it is because it's very hard. Breaks almost everything that I tumble with it so I'm going to have to cut up a few more bits to tumble. But, I'm doing it because it looks like it will tumble out interestingly. Hey, people will tumble just about anything so like I said, if you like it, go for it!
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markward
off to a rocking start
Member since December 2006
Posts: 23
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Post by markward on Jan 10, 2007 16:37:33 GMT -5
Hear what you are saying and thanks for your comments, My reasons for not polishing it was not really because it was man made but from what it was made of... as this stone was only made to look pretty from the outside edges the inside was like a basic solidified cement/sand.
i have got some of that gold rock you mentioned....i bought it labelled as Goldstone and have heard that it polishes a treat..
i have also got some blue obsidian man made which i will also polish in time.
I take back what i said about not polishing it as i will give it a go but it will be placed down the pecking order..hopefully i will be surprised...
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