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Post by krazydiamond on Jul 12, 2004 19:26:38 GMT -5
are there various types? i got some stuff in a mystery mix that seems REAL soft and light (like charcoal) and i guessed (perhaps mistakenly) it was pet wood, then i read where pet wood was extremely hard and i ended up with what i think is that too in a different mix( almost agate-y)...the stuff that is soft is SO pretty and LIGHT!! i am going to buy some barrette findings and make some with this stuff if it polishes nicely. the real question is, if you are happy with the shape of the stone, can you skip steps and go right to polish? or is it necessary to pre-polish for a good finish? thanks for your input, KD
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lotarocks44
having dreams about rocks
Member since April 2004
Posts: 54
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Post by lotarocks44 on Jul 12, 2004 20:04:09 GMT -5
hey kd thats what i was talking about not leaving it in the tumbling long enough I want a goo shine.what i understand is that pet wood is an agate i have some in the picture with my agate i tumbled them all together so i guess it is about the same hardness
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rollingstone
starting to spend too much on rocks
Member since July 2009
Posts: 236
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Post by rollingstone on Jul 12, 2004 20:18:52 GMT -5
KD, petrified wood can vary a lot in hardness. I find a lot of it in river gravels, and some of it is very agatized and hard and polishes nicely. Other stuff is maybe not fully replaced with silica or something, but it certainly grades into that charcoal stuff you are talking about -- very brittle too. Occasionally this will polish, but usually I chuck it out as more often than not it won't shine. There is also some soft whitish material that seems to occur with petrified wood sometime, and this is pretty, but rarely do I find it hard enough to take a shine. Annoying thing is a fair bit of the petrified wood I find is a mix of agatized wood and the whitish material, they are sort of intertwined. When I polish it, the agatized parts shine brightly, and the white parts stay dull. On rare times, the white part will take a shine. But lately I've been sticking with the agatized stuff only, because I know it is hard enough to shine.
Recently I found a piece of petrified wood that was a very neat translucent black colour. It would polish really nicely I'm sure, but I like it so much as is that I'm not going to crack it up.
I guess the point of this is that when you buy petrified you probably get only the agatized or chalcedony kinds that are sure to polish. But "field" petrified wood can be very different sometimes.
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duke
noticing nice landscape pebbles
Member since May 2004
Posts: 77
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Post by duke on Jul 12, 2004 20:25:18 GMT -5
KD.. I think most pet wood is about the same hardness as agates, but I think maybe the pet palm wood might be a little bit harder...(just my personal opinion)..and there are times(not often) when there are streaks/bands in the pet wood that are softer than other parts..so you get sort of mixed results when tumbling...but I think most pet wood is as hard as agates and I have tumbled them together, and am doing some right now.. I haven't tried to skip steps and go right to polish, so I can't answer that part of your question..try a few and see how it comes out.
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Post by stoner on Jul 13, 2004 1:13:24 GMT -5
Hey KD. To get the best results when tumbling stones, it's best to stick with the basic 4 step program. Each step is needed to remove the scratches from the previous grit before moving on to the next step. You can increase or decrease the amount of time spent in each step, but you shouldn't skip a step. If you are tumbling beach rock that is already rounded and relatively smooth, then you can MAYBE skip the 60-90 grit. That's my take on this, anybody agree/disagree?
Ed
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rollingstone
starting to spend too much on rocks
Member since July 2009
Posts: 236
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Post by rollingstone on Jul 13, 2004 2:10:42 GMT -5
I agree with stoner, stick to at least a 4 step program and don't cut corners. Polish will take out the scratches left over from pre-polish, but it can't take out the scratches left over from fine grind, unless you are willing to leave things in polish for a very long time. Even with really soft materials I think you should stick to at least 4 steps, but maybe just run them through each step quicker. I think deepsouth has successfully cut out 60/90 for beach stones, but I'm chicken on even that one, so I usually toss beach stones in coarse grind for one cycle. Back to my earlier ramblings about petrified wood and how it isn't all like the stunning stuff in Petrified Forest in Arizona. Here is a piece of petrified wood I found and split in half...the bottom part shows the outside of the piece, and the top half shows the carbonized interior. This piece is heavy as stone, not light like KD mentioned, but it is useless for tumbling. And here is a piece that is very dark and glassy in this cross-section (as found in the river, not cut by me), and would be wonderful for tumbling. But I can't bear to chop it up. Seems to have the concentric tree bands nicely preserved, but maybe that doesn't show up too well in the photo? But most often I find stuff something like this. It has lots of bands that I like to think are tree rings, but probably really are not because they run lengthwise, not crosswise and circular like in the previous photo. So they maybe are some agatized bands that formed as the wood was slowly replaced with silica. but notice that there is a whiter band across the top of the piece. What's the problem with the white band? In many stones it just won't polish. I think the band in the previous photo would take a shine, but I'll never know for certain because it is another piece that I can't bear to smash up. But here is a photo of some polished pieces of local petrified wood, and I hope you can see that the darker material took a shine, while the white material refused to. If nothing else, it should show how intertwined the lighter (softer) and darker (harder) area can be. BTW, if anyone asks me something about this post, don't get miffed when I don't respond, as I'm away for the next week or more.
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Post by puppie96 on Jul 13, 2004 3:35:47 GMT -5
Rollingstone, these are great photos. Very interesting. I keep trying to determine what is pet wood and what is something else, since most of the pieces I see in real life and in photos just doesn't look very different to me from the usual agate/jasper/chert/flint group -- I've got zillions of backyard rocks that I suspect might be pet wood but I'm really not sure. The ones that you posted have a distinctive look of wood. The second one, the really pretty rock you are holding in your hand, to me doesn't look obviously like wood at all. Can you help me out here?
Regarding the beach stone issue, with nicely shaped ones that don't have a bunch of obvious surface defects or anything, I definitely skip 60/90, especially if they are on the small side, to avoid excessive loss of volume. They polish fine.
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rollingstone
starting to spend too much on rocks
Member since July 2009
Posts: 236
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Post by rollingstone on Jul 13, 2004 4:48:03 GMT -5
Sure puppie, here is the same piece of rock photographed from the side instead of across the grain: Because it has such a wood-like exterior when shot from the side, and because it shows concentric growth rings when shot across the grain, that's why I'm certain it is petrified wood. I should note however that I've only ever found two pieces like this...this one here, plus a much smaller chip of probably the same piece of wood, found about 30 feet downstream. With the smaller piece, it had no outer rind or visible rings, so I didn't really know what to make of it until I stumbled on this "mother piece" just upstream.
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Post by BearCreekLapidary on Jul 13, 2004 9:53:28 GMT -5
Hello KD,
We have some petrified wood in the central area of Kansas that has nice exterior details, but it is not worth even trying to cut or tumble. This petrified wood has been replaced with calcite, and not the higher grade of agatetized material. It is chocked full of tiny crystals. I would have to do some looking to se which geologic formation it lays in ... but, it's definitely not suitable for tumbling or cutting ... only as a collector's material.
I have found a wide range of petrified wood, and like a lot of other material ... there is good and there is fair and then ... there is the ?, that won't be of much use, piece!
There is also the following kinds of petrified wood that works up beautifully: Jasper/Agate Wood and Opalized Wood. I have found that the opalized wood is generally severely fractured and can be broken into smaller pieces really easy ... but, it might be worth a good tumble run! If you are very lucky you might even run across a piece of opalized wood that has a little fire in the opal voids of the wood. I have a piece of opalized wood from Australia - Lightning Ridge Area (somewhere, I don't know where it is ...) but, it shows a nice blue and green band of fire within the opalized wood - very interesting!
Enjoy,
John
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Post by krazydiamond on Jul 13, 2004 19:44:52 GMT -5
i was in a jewelry store today and i think i saw some of what you described, John....it was absolutely gorgeous Opalized Wood. a little pocket set in to a piece of wood, i marveled at it, a coincidence you would mention it......
i was getting some watch batteries replaced and i was eyeing up all the (very expensive) stuff that almost seems within my grasp to make now....
ok, what i have then is some of both the junk type charcoal stuff and someof the striated agate stuff..i still think i can do something to make the pretty stuff shine (oooo, cuz it loooks pretty crappy when it dries out and there is grit in the grain.) why would they send the crap stuff in a mix if it wasn't "tumble-a-ble"?? this was froma reputable dealer...(mamasminerals).
thanks for the answers, tho, and nice pics, rollingstone, have a great week off, where ever you roll to,
KD
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tarylina
noticing nice landscape pebbles
Member since May 2004
Posts: 84
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Post by tarylina on Jul 14, 2004 21:25:57 GMT -5
KD -
I'm running petrified wood from the Rock Shop right now and it's pretty hard, been two weeks in rough and still going. It looks like the pic from rollingstone but a little smoother and more tan.
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Post by sandsman1 on Jul 15, 2004 9:49:16 GMT -5
hi all --i think i got this from the rockshed in a mix bunch not realy sure but it came out realy nice and shiny,, i maDE MY daughter two pendents she said she realy liked them
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