Best Polish

Aluminum comes in many grades. Most "tumbling polish" will be in the 3-4 micron range and will polish in a rotary or a buff pretty much anything cerium will. Finer aluminum oxide (submicron) will polish a wider range of rocks, works better (generally) in a vibe tumbler, and will equal tin oxide in most cases. Whenever ordering aluminum insist on the micron rating. Aluminum comes in 600, 800, 1200, etc. all the way to .2 micron. The better submicrons will be .5 and finer. Price goes up as particle size goes down, generally.

I've used a lot of high grade cerium oxide and even the real expensive optical grades of both cerium and tin oxide. I do mostly quartz materials and none of these has ever produced a shine any better than the grade of AO the Rockshed sells as a polish for a really reasonable price....Mel

bpaul: You know, I've never really seen the particle size on the tin or cerium oxide. My assumption would be that they are somewhat finer than the AO because, generally, I've found them to polish faster and the tin and cerium often do a better job with softer materials. I always use optical grade cerium or tin on things like travertine or other calcite hardness stuff with great results. Other than those two things, I can think of no other advantage because even though I'm pretty sure the Rockshed AO runs between .5 and 1 micron or so, I run it a longer time for polish so it would break down to smaller size anyway and it does an awesome job on quartz gem tumbles. Cerium oxide comes in several grades all of which are much more expensive that AO. Both the CO and the TO are four or five times the cost of the AO with the optical grade being even somewhat higher which makes them very pricey for tumbling....Mel

i've never been able to get much of a shine with cerium oxide, perhaps i wasn't using the right kind? anyway, i've tried all the expensive ones (tin oxide, etc.) and finally settled on a fairly inexpensive (compared to others) polish called CPP, available at Alpha Supply company. Unfortunatley, their websitte has been down for some time now. you can also get it at Mama's Minerals:

www.mamasminerals.com/page/MM/PROD/EQT-CPPPO

it is Aluminum Oxide, btw, it works for me.

KD

Mel,,,,

Are you sure the polish is breaking down?

connrock

For nice hard agates, jaspers, etc., try polishing with Ivory soap. For a 6# rotary tumbler, put rocks, water, and a half-bar of Ivory in the tumbler & run for two weeks.