Roan
has rocks in the head
Member since January 2008
Posts: 600
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Post by Roan on Mar 4, 2008 21:54:40 GMT -5
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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 Mar 4, 2008 23:05:16 GMT -5
You are right that ruby is very hard. Silicon carbide tumbling grit is mohs 9.1-9.3, and ruby is 9.0, so tumbling it will take awhile. It shouldn't be anywhere close to a year though because you are starting off with quite small pieces so they won't require a whole lot of shaping.
One strategy with ruby is to run it in coarse grind with agates or other quartz-hardness materials (using 60/90 or whatever grit you usually use for coarse grind), and let the ruby actually act a bit as grit for the agate. That is, the ruby can help to grind the agate, so it isn't like you are just running repeat barrels of coarse grind with just ruby in them. In turn, the larger agate can help the grit to grind the ruby faster.
Once you are beyond coarse grind, I would put the ruby into the finer stages several times over, with agate or whatever as the filler. You could run the ruby by itself to avoid having the ruby scratch the agate, but this shouldn't really be much of a problem because the ruby should be pretty smooth at this point so shouldn't cut into the agate. Anyway, the reason I say to run each of these stages several times is because the 1 week per stage rule is really designed for mohs 7 and softer materials, so I'd go several weeks with ruby to give the grit a chance to do its job (and you have to change the grit after each week or so because the grit will break down).
For polish, make sure you use aluminum oxide (which is powdered corundum, at Mohs 9 equal in hardness to the ruby... actually, ruby is a form of corundum). Other polishes aren't hard enough to polish the rubies. Except for diamond of course, but you'd need some deep pockets for that. ;D
I know that somewhere in this board, in the old members photo section, there is a bit of information on tumbling rubies. I think the search feature isn't very good though, so it might be difficult to find.
Good luck!
-Don
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oriongal
noticing nice landscape pebbles
Member since May 2007
Posts: 96
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Post by oriongal on Mar 5, 2008 0:20:31 GMT -5
I have been playing around with some corundum off and on for around nine months. Being still quite a newbie to this hobby, I wouldn't take the results I've had as necessarily typical. I'm a tinkerer at heart and I've had fun playing around with these, but don't know that I'd have had as much fun with them if I'd been completely serious about getting a good result out of them. This was the last batch of rough that I got - I think this batch came primarily from MSI (Multistone Int'l). Shown mostly dry:  This is after a month or so in coarse (60/90 SC), with some that I'd done previously also added back in (some of the previous had spent a couple of months in coarse):  Overall batch about a month after the previous pic, still in coarse. They did shape up pretty well from where they started:  Unfortunately I don't have pics of the later stages - mainly because in the winter we have so little sunlight, and I was so busy. I think they spent about 7 weeks in medium, and then I started experimenting a bit from there. What I found over time, is that the pitting on the stones did not ever go away, no matter how long they'd been in coarse. Or medium. There is one bluish-greyish stone in the middle pic above, to the far right and larger than its neighbors (and around top center in the third pic)...that one got started with my first-ever batch of rocks, and I suspect that it has spent a grand total of 4 months in coarse grit. It started out as a hexagonal shape and nearly half-dollar size. It's now about quarter-sized, nearly spherical - and still every bit as pitted as it was in the pics above. So at this point, I started experimenting. I started moving some stones on even though they were pitted (after burnishing to make sure they weren't harboring grit), and some of them surprised me with showing more improvement in a grit stage they weren't really ready for (prepolish, polish) than they had the entire time they were in the previous stage(s) that should have smoothed them out more than they did. So now, I've got some in fine, some in prepolish, and some in polish - just to see what they do over time. I also took some of the smaller ones and threw them in the KG-1 with some 14,000 mesh diamond paste about 48 hours ago. I went and fished out a few from the regular polish and a few from the diamond-paste group, rinsed them off and took some pics of each. They're definitely nothing to write home about, but it's overall been an interesting experiment... These are in regular Lusterite polish, and have been for about a month. They went in very pitted, and they are still pitted - but surprisingly they are also slowly smoothing out on the flatter surfaces. I didn't figure that Lusterite would be hard enough to put *any* polish on them whatsoever, that was rather unexpected.     These are the ones that just went into the diamond paste trial. They had previously been in AO pre-polish, for probably a month or so (as had the above). They're definitely showing more improvement, and faster, than the ones in regular polish - as one would expect. But as Don mentioned, I wouldn't want to do a large batch this way - diamond anything isn't cheap.   I haven't yet taken a Dremel to any of these, but I suspect that with a diamond wheel and/or diamond paste on a buffing wheel, I could probably get a shine on a couple of them...before wanting to throw them across the room in frustration, that is...<grin>. It's been interesting to see what they've done along the way in the tumblers, but I don't think I'd have the patience to do very many of them by hand. My experiment, for what it's worth...  |
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Roan
has rocks in the head
Member since January 2008
Posts: 600
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Post by Roan on Mar 5, 2008 0:26:38 GMT -5
That is AWESOME, oriongal! Thank you very much for your input. I'm going to read that over and I'll have a zillion questions in the AM.
If I could get my hands on a pound of diamond dust, I think it's 40grit, would that help?
Eileen
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oriongal
noticing nice landscape pebbles
Member since May 2007
Posts: 96
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Post by oriongal on Mar 5, 2008 0:35:49 GMT -5
I don't know. The coarse SC grit did fine at taking the edges off the stones, and the medium continued doing all right at that - it just didn't take out the pits nor smooth the surfaces no matter how much stone it wore away.
On that, I have no idea whether the problem is/was technique (i.e., me being inexperienced in general), or the use of SC vs. diamond, or whether it's just poor quality rough that isn't going to improve no matter what you use on it. It is the typical mine-run stuff, not likely to be considered even cabbing grade.
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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 Mar 5, 2008 0:40:40 GMT -5
Oriongal, nice write-up! That's got to be the most complete guide to tumbling rubies I've seen in almost 4 years of browsing this board!
-Don
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rallyrocks
fully equipped rock polisher
Member since November 2005
Posts: 1,507
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Post by rallyrocks on Mar 5, 2008 0:49:43 GMT -5
If its nice dark red shiney things you want for your trees, you might consider Garnets rather than ruby- less expensive and better "gem" quality for the money I'd think.
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oriongal
noticing nice landscape pebbles
Member since May 2007
Posts: 96
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Post by oriongal on Mar 5, 2008 1:11:47 GMT -5
<blush>...thanks! But I don't know that I'd call this any sort of successful guide to tumbling rubies, though. Especially since they haven't turned out anything near what I've seen come off a cabbing machine (for similar-grade stones). I do wish now that I'd kept notes on how long they actually spent in each stage as well. I know that I was changing the grit about once a week throughout. I'll probably continue to leave them where they are unless they get to a point where they're not showing any change at all for a long time.
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Roan
has rocks in the head
Member since January 2008
Posts: 600
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Post by Roan on Mar 5, 2008 6:39:28 GMT -5
If its nice dark red shiney things you want for your trees, you might consider Garnets rather than ruby- less expensive and better "gem" quality for the money I'd think. Ruby is July's birthstone and its alternate is carnelian. Unfortunately, of all the months it seems that July babies don't want substitutes. Gotta be rubies for them and I don't have a problem with that since the price of a ruby tree would reflect the extra costs involved. I do have garnets, btw, and they are annoying to work with. Dang things are ROUND for the most part and when I find a nice flat spot that would sit on a branch just right, chances are it's the best part of the chip. Heh. Eileen |
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Roan
has rocks in the head
Member since January 2008
Posts: 600
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Post by Roan on Mar 5, 2008 6:45:07 GMT -5
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L.L.
starting to spend too much on rocks
Great Pyrenee?s Lover Extraordinaire
Member since January 2008
Posts: 135
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Post by L.L. on Mar 5, 2008 14:07:25 GMT -5
You guys and gals are a wealth of knowledge. I have a few pounds of ruby and sapphire rough that I've been leary about even bothering to tumble. I was under the impression that it would take diamond to get a really good polish on the stones. I don't know if a have the patience to even get them to that point. Sounds like they would tie up a tumbler for quite a while.
Lee
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Roan
has rocks in the head
Member since January 2008
Posts: 600
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Post by Roan on Mar 5, 2008 16:22:57 GMT -5
A vib would cut down the tumbling time by quite a bit, wouldn't it? Hrm. May be just the excuse I need to convince hubby that I need to buy another tumbler ;D
Eileen
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oriongal
noticing nice landscape pebbles
Member since May 2007
Posts: 96
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Post by oriongal on Mar 8, 2008 17:40:33 GMT -5
Some more pics from today - cutting out the camera flash gives a better idea of where these are (all are clickable): The problem that I'm seeing with them seems to be that the layers they're made up of just keep getting worn away - but not smoothed over, at least when using SC grit and regular polish. Here are a couple of pics of that, the first showing the layers and then how they've been worn away: Here you can see the layers (they are silvery, which is why I'm assuming they're alumina):  And here, where they've worn away rather than smoothing over (this stone is in regular polish now, btw):  And this one shows it even more - it spent a very long time in coarse, medium, fine and prepolish, and still looks like this:  Then turned, so the layers catch the sun:  These are a few fished out of the regular polish barrel - not burnished, just rinsed off and let dry. Some have smoothed out from where they were when they went in, but as you can also see, some still look like they need to go all the way back to coarse. Problem is that it wouldn't do anything except wear them away more:  These are some fished out of the diamond run, rinsed off and let dry. They've been in there for a week now, and many of these looked a whole lot like the above when they went in. Definitely more improvement here than with regular polish or prepolish. The arrows I've drawn are pointing out two of the stones that are oriented just right to catch the 'flash' I was talking about in the other thread, which is coming from within the stone rather than from its surface:  A couple more pics trying to catch that flash from within the stone - shown oriented where they're not showing it and then where they are. Unfortunately on these my camera decided that it wanted to focus on the background more than the stone, but you still can get the general idea on them: Without:  With:  Without:  With:  And then last, both groups shown completely submerged in water. Any flash that you see on these stones is coming completely from within the stone itself, because the stones are completely underwater: Regular polish group, submerged (there is a stone in the lower right that is showing some flash):  Closeup of lower right stone, and you can also see the reflection from the water's surface in the upper right to see that it is submerged:  Then the diamond-run group, submerged:  And in this submerged group, I probably caught the best example of the flash I'm talking about - arrow points out the stone with, and without:  Without (doesn't even look like the same stone):  |
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