herchenx
Cave Dweller
Member since January 2012
Posts: 3,360
|
Post by herchenx on Feb 4, 2012 4:20:12 GMT -5
Well I have ended round 2 of stage 1 on the 2x6# lortone barrels. I had high hopes, at the end of the first time around things looked pretty promising on the number of different rocks, I thought we'd have a whole mess ready to move on to stage 2. No such luck. I opened the barrels and things initially looked very promising, way more rounded than last time. But as I carefully inspected each one I still found tiny pits and cracks. What really took the wind out of my sails though is that all the "eye' jaspers seem to be losing their eyes. A lot of them are nicely rounded but the eye's have started to undercut or completely disappear. Large pits are forming in many of them and they are all getting appreciably smaller. It is sad to see these beautiful rocks wear down so much. Some have thinned in places and have started to crumble along edges. Other ones have exposed fissures in the rocks and eroded those badly when last week they seemed nearly smooth. I considered saying "to heck with it" and pushing them all to the vibe for stage 2, but I want these to be as good as they can be, so I put them all, save 10 or so teeny ones that are completely smooth, back into the 2 barrels and charged everything. I did add some jasper saw scrap to fill them up a little, as well as a couple pieces of wonder stone. Here are the contents of the larger barrels before I restarted them: When I charged these up for stage 1 last time, I also set up to small 1.5# lortone barrels with a bunch of pea-sized garnet rough. I added some of the smaller agates from the larger barrels into one of the small barrels, the other barrel was all garnet. I opened them both to a nice slurry: I rinsed them both off, and separated out the garnet into one barrel and put all the other jaspers and agate into a separate barrel, adding in the new small stones from the larger barrels. The dedicated garnet barrel I charged with 3Tb of 46-70 (coarser than I have been using, but the garnet was unscathed it seemed after the 60-90 round. I charged the agate/jasper barrel with 3Tb of 60-90 and set everything back to tumble. Then I started into some new cabbing stuff that I'll cover in the cabbing forum. Thanks for reading!
|
|
catskillrocks
fully equipped rock polisher
Member since July 2008
Posts: 1,270
|
Post by catskillrocks on Feb 4, 2012 8:33:10 GMT -5
I hate it when that happens, when the best features of a stone are nearly ground away or undercut or keep on getting new pits etc. Good Luck with that batch.
Don
|
|
Sabre52
Cave Dweller
Me and my gal, Rosie
Member since August 2005
Posts: 20,456
|
Post by Sabre52 on Feb 4, 2012 9:50:40 GMT -5
OK a couple of things. First off, garnet is harder than lots of agate or jasper and will chew them up just like grit will. Garnet can run as high as Mohs 7.5 while only the purest agate is a 7. That's why garnet takes longer in coarse grind because it's closer to being as as hard as your grit ( mohs 9+) so the grit takes awhile to wear it smooth. It's a pretty bad idea to run mixed hardness batches because of the potential for the harder rocks to damage the softer.
Your tiny pits and fractures etc fall into the garbage in garbage out category. If the pits or fractures are deep you've got the choice of grinding them a long time to wear them away or chuck the stone. When I go through my barrels each time I recharge, I sort and throw out any really defective stones that I figure will take too long to wear smooth or will never wear smooth. It's very important to sort your rough before you even begin your tumble to make sure all stones are of similar hardness and free of defects to bad to grind away.....Mel
|
|
|
Post by helens on Feb 4, 2012 11:50:26 GMT -5
I can't say I have much experience tumbling, but I was pulling out stones to compare every 2 hours (or less) the entire time I have tumbled, and the one thing I learned was that harder stones will DESTROY softer stones very very quick.... as in grind them down to sand. If you are pulling rocks out every 2 hours to compare, you will see it happen before your eyes.
The only reason I comment here is because in your top batch, you had some incredibly beautiful ocean jasper... these are just gorgeous, and I would never put them in a tumbler with anything harder than themselves.
I think with every batch, you have to decide WHICH stone you most want to polish, and tailor your entire batch to cater to that stone. In my case, it was opals.... did I want to lose a whole lot of money in opals because I also wanted a handful of agates tumbled? No... out came the agates. I did not realize what they were doing to the opals til hours in... and it was a darn good thing I was obsessively checking them every few hours, because after 48 hours, I would have had not a single opal, not even dust, if they stayed in with the original fire agates in the batch I had.
I'd put nothing but ceramic media or glass pieces in with the ocean jaspers if it's not too late, so the ocean jasper are the absolute hardest thing in the whole tumble.
And given the hardness of garnet, I'd pull anything that mattered to me out of that batch and run it with fillers that I am prepared to lose completely (down to 1/4 inch, at which point you should take them out of the tumbler and probably throw them out since they won't be polished).... and keep adding more and more filler as the garnet eats it up every 12 hours.
But I'd remove all the pretty agates very fast before you have none left from the garnets:(.
|
|
herchenx
Cave Dweller
Member since January 2012
Posts: 3,360
|
Post by herchenx on Feb 4, 2012 12:51:47 GMT -5
To be clear the garnets were in the barrels with just some chips and pieces of small agate. I did separate the garnets into their own barrel last night as well, so no more garnet-agate mix.
These are my first tumbles so I am chalking everything I do up to a learning exercise. I did buy decent rough from the gem shop, so I don't feel like I bought "garbage"rough. I do think I might try preforming the next time around though, cut the Bahia's open, grind out pits etc.
It seems like the round eyes in the ocean, bahia, and others is what is most vulnerable. I am not sure how separating the ones with eyes would help them, as they are still in with other hard jaspers.They are much smoother and rounder over all, just losing their eyes.
|
|
Sabre52
Cave Dweller
Me and my gal, Rosie
Member since August 2005
Posts: 20,456
|
Post by Sabre52 on Feb 4, 2012 15:07:38 GMT -5
Sorry Herch, I did not mean to imply all your rough was garbage but I was saying that in every batch of rough there will be pieces that are simply too pitted, fractured or flawed to bother with as is. It's usually simple to sort these out after the first round of coarse grind and either chuck them out as I do, or give them some grinding or break them up to make them into more suitable pieces for the tumbler Ocean Jasper, while very beautiful is a problematic rough due to the presence of a lot of vugs or voids and the fact that some pieces are of mixed hardness due the presence of megaquartz. The quartz crystal sections are usually not as hard as the more solid areas of agate. Still a wonderful stone but you just have to accept the imperfections as part of the character of the stone.
I've got my first batch with Bahia agate in it running now and it appears to be a stone that will have a few problems as many appear fractured. I often do exactly as you've said with a lot of rough and take it to the trim saw first, make clean slabettes and tumble those. Since then you can see what's on the inside first, those usually yield clean stones which are often very nice for pendants and such....Mel
|
|
meta99
has rocks in the head
Ohio Flint Ridge flint
Member since October 2010
Posts: 540
|
Post by meta99 on Feb 4, 2012 15:46:24 GMT -5
John: I'm throwing all sorts of crud in my rotaries. When I bought out this estate, the old guy did what we all do and save trim scrap. I have all these really tiny triangles from his cabbing days! Some of the rough I have is too pitted or fractured but since a lot of it is softer than the agates and jaspers, I leave it in as cheap fill, saving my ceramics for my vibe. In the process I'm finding some things that weren't supposed to be in the tumble stuff, like some of his faceting rough! Nothing like surprise rubies and garnets! So I just run it all and chalk it all to learning experience like you. In the process, I have some nice pendants I'll be able to make (a lot like Randy's) so I had to go buy some bell caps with eyelets for a jump ring. Besides, I'm having a blast! Sue
|
|
herchenx
Cave Dweller
Member since January 2012
Posts: 3,360
|
Post by herchenx on Feb 4, 2012 17:15:38 GMT -5
Got it Mel, I just need to learn when to cut my losses on stuff, good words. Thanks again to all for the input.
|
|
Minnesota Daniel
freely admits to licking rocks
A COUPLE LAKERS
Member since August 2011
Posts: 891
|
Post by Minnesota Daniel on Feb 5, 2012 2:38:59 GMT -5
I recently acquired some "birds eye jasper" and it is nice looking stuff, but I would call it rhyolite myself. It's hard for rhyolite to be sure, but it's not as hard as any other jasper I've tumbled. It's not nearly as hard as an agate. I threw 2 pieces in with a mixed batch of agate and jasper to see how they would fare, and the eyes did wear down to nothing in no time. I'll be tumbling the rest of the stuff by itself, which is what I figured I'd need to do when I was pickin' through the stuff in the bin.
|
|
Sabre52
Cave Dweller
Me and my gal, Rosie
Member since August 2005
Posts: 20,456
|
Post by Sabre52 on Feb 5, 2012 9:40:46 GMT -5
Yeah, those bird's eye or orbicular types of rhyolite vary greatly in the amount of silica present. I bought some saw scraps from Ralph and Mary Ann that had a few pieces of Flor de Chihuahua included. That particular form of bird's eye rhyolite is jasper hard is hard. I ran it with mixed agate and jasper and they took a fine polish. Probably best to do most forms by themselves though...Mel
|
|