slabs and vibe tumblers

I don't know what others have, but I have a "Berry's Blue" vibe - with a big blue bowl - about a gallon and a half capacity, roughly. I have 2 bowls - one I use for the coarser grits - from 120/220 up through 600, and the other for the pre-polish and polish stages. I burnish for 2-3 hours with Borax between grits, and I do use the same bowl for the burnish as was being used for that particular stage.

I think you'll find that you will have to be cognizant of what kind of stones you are putting into a load in the vibe - you want everything in a load to be around the same relative hardness - ie, don't mix quartz and agate with something like flourite or a softer stone - the softer stones will disappear, having been ripped to shreds by the hard stones. I don't know what stones you have in this load, but that might be the cause of the non-shiny bits.

Tom

What Randy said. The problem with flat surfaces is the difficulty of getting contact between the stones. A lot of rounded stones in mix helps as would up to 50% ceramic media. There have been many posts on this subject but I'm not sure how easy they are to find.

Thank you all for the replies.
The rocks and slab pieces were already in the tumbler when I got it. My friend gave the tumbler to me. He didn't know what stage the rocks were in or how long they had been in there or how they were treated before polishing. I washed them off and they seemed to be partially polished so I started them on pre-polish grit (500). Did that for two days then washed them and put them in a different bowl with AO and ceramic pellets. The slabs are small, most under 2" across and are combined with small round rocks. All are the same basic hardness, ie..quartz - jasper, petrified wood, agate. This guy knew what he was doing but stopped doing it because he didn't have the time about 10 years ago so couldn't remember what exactly he did. He gave me some of his polished stones and slices and they are nicely polished.
It does look like the edges of the flat stones are polishing now that I look closer so maybe it is that they just need more time. Would it hurt to leave the round rocks in the tumbler even if they are already polished?
Do I perhaps need to refresh the AO?
Thanks again

Thanks rockdewd that eases my mind. I'll just leave them in for a bit longer and see what happens.

Will do Warren.
If I was home more often I would be able to find out the results sooner rather than later but I run it when I can. Hopefully I'll have the load finished before the snow flies or it gets too cold to keep the tumbler outside.

Running a couple of cups of tempered glass shards with a load sometimes helps as the little pieces make for more contact surfaces with the stone. The little pieces break down to little nothings but do seem to help speed things up somewhat ! Makes for a REALLY cheap filler as the glass stores will almost pay you to haul it away. To break an old tempered window safely, lay it on a tarp and just tap straight in on one of the corners and it will pop without glass going everywhere. Then grab the corners of the tarp and dump all the little treasures into a bucket without a lot of mess.