Zirconia polishing beads

I was about to ask the same question. I recently bought a kit of grit. Because I only tumble small batches in 1.5 lbs tumbler, I tend to get the kits instead of the large quantities. This is the first time I ordered this kit, and it came with 1lb of zirconia pellets. I haven't made it to setp 4 with my current batch, so I was also wondering if anyone has used them in the polishing step, and if they are any better than ceramic media.

I finished my polish batch with the zirconia beads, and overall I am quite pleased with the results. I would be hard-pressed to see a real difference between polishing with ceramic pellets and zirconia beads, even when looking up close with a jeweler's magnifying glass.

My tumbling process was the same for the 2 test batches.
Equipment: Lortone 33B tumbler with 1.5lbs barrels.

1- at least 2 week-long tumblings in 60/90 silicon carbide coarse until I got the bumps out and smooth shapes. I rinsed and recharged the grit after each week when the shapes were not ready, sometimes adding new rough rocks to top up the barrel.
2 - 7-10 days in 180/220 silicon carbide
3 - 7-10 days in 500 silicon carbide
4 - 7-10 days in Alumina polish (1500 I think?) with the ceramic pellets in one barrel and zirconia beads in the other.
5 - 12-24 hours in borax for final clean and burnish, with the respective media included.

The shine in the 2 batches for rocks that I think are good comparisons in terms of hardness and colours is nice and about the same.

A few observations:
- one thing I really like about the zirconia beads is that they are smoother right out of the bags, whereas the ceramic pelles feel a bit more rough. The ceramic pellets feel smooth after a couple of tumbles. I used ceramic pellets that had already gone through at least one tumble for this test, so I would say that there smoothness was similar to the new zirconia beads.
- the zirconia beads are all pretty much a uniform size. I don't know if this matters much in ensuring the grit or polish goes around and grinds to rocks evenly. Based only on my first polish test, it looks like they work equally well.
- For my next batches, I might try using the zirconia beads in step 3 as well to see if they help, and how well they stand up to grinding.
- I read somewhere that the zirconia beads might last longer than the ceramic pellets before grinding down, especially if used in the earlier stage. Only time will tell.


So I think it comes down to preference and availability of the media (and price of course). I had never seen the zirconia beads anywhere else before.


This photo shows some examples from both batches. On the left are rocks polished with ceramic media in step 4, and on the right are rocks with the zirconia beads in step 4.

All of these rocks came from New Brunswick (Bay of Fundy) and Prince Edward Island (West Coast) in Canada.

I've never heard of zirconia being used as media.
I double checked to make sure...
Zirconia has a hardness over 9.
If they ever broke up or chipped I'd think they would scratch the stones fairly easily.
However the photo you posted shows great results.
If anything just be sure and inspect to make sure you're not throwing any jagged edges in the barrel.
Thanks for sharing 👍

From what I could read up on it, it looks like it is a composite of zirconia and ceramic. They are nice and round and did a pretty good job, so I'll keep using them to see how fast they wear down compared with my ceramic pellets. 

Fun fact.... most white ceramics that are not made for food contact (due to the expense vs clay based ceramics) are zirconia including most, if not all, ceramic filler media for tumbling.  The most common formulation is zirconium dioxide or ZrO2

ZrO2 ceramics are also used extensively in ceramic ball bearings due to their extreme light weight to high load bearing ratio & high durability.

***Mind blown***
So, you're saying that my zirconia beads are most likely the same as my ceramic sticks, just different shapes? 
I can say I learned something new today :-)