National Geographic GemFoam Reusable Rock Polisher for Rock Tumblers

facile a utiliser apres avoir utiliser mon 1200 grit

Easy to use, but doesn’t perform anywhere near the advertising

First and foremost this review is for the foam pieces. I noticed the reviews are all mixed for different National Geographic rock tumbling products I am very pleased with the foam to use after step 4 which as others have stated left the rocks or minerals still very dull not shiny, this got the job done. Just use it after step four if you were using National Geographic grit as instructions suggest. I am also getting a better step 4 from another brand to compare that with the foam to see if it does better or the same as foam but as for now I am very pleased. Here in this photo I tumbled a chert in the foam after Nat geo 4 step. Chert is the stuff you commonly see in Some concrete It has a hardness of seven I'm thinking that at least for the foam anyway the harder the rock the better they shine like this one does quite well. I am currently tumbling a less hard rock serpentinite with hardness of four or five and it’s not getting quite as shiny but I think it’s still better than before, I am letting it tumble longer. So Basically if it’s a six or seven or harder it will shine better using these whereas step four did nothing using National Geographic. It’s cool that these rocks in the photo came from my backyard doesn’t look like something from a backyard once you shine them up like this pretty cool Update: The pictured rocks turned out amazing, however the serpentinite never got shiny. My conclusion is that these foam pieces only work for harder rocks that are somewhat smooth to begin with. The rocks in this photo were somewhat smooth to begin with but not shiny the foam without a doubt made a huge difference the light did not bounce off them like it does now also they are now silky smooth as opposed to somewhat smooth. So if you use these bear in mind they will only work for harder somewhat smoother rocks. I did use a better step 4 for my serpentine and I still see no difference so just like with the foam I think some rocks are just not going to shine as well as others. The foam still gets a five star for what it did to that chert though and you do need to go the full 3 days of tumbling because after day one I saw no results. A total of five days in the foam wouldn't hurt either I was pleased with 3 though.

These work great but very overpriced!

Great tumbler. Use it frequently with no problems.