The Grounded Rock Hound

Oh Christmas Tree, Oh Christmas Tree…

My youngest son is one to dabble in many activities… hobbies really. Lately, the two he is most strongly drawn to are Karate and rock polishing. If you give it some thought, the two activities are akin to each other… both take; attention to detail, preparedness, and patience. He has taken steps forward in each. In Karate, he just tested successfully for his yellow belt. He is still early on the in the process, but we are very proud of his accomplishment. As to the other activity, just yesterday, on Christmas morning, he opened one of his presents and could not contain his excitement… mind you, most 9 year olds would react quite differently when opening a box of rocks on the “biggest day of the kid year”. He’s always wanted to learn how to polish rocks and he’ll be starting on this new hobby as 2016 winds down.

So… how does one polish rocks, you ask?

We’ve actually found some excellent on-line resources and have started our first batch. Several of my son’s gifts were aimed at rock polishing this Christmas… they included; a rock tumbler, several different polishing compounds of varying grit, and yes, a box of rocks : ) I will admit that we purchased all three items on Amazon and after performing a bit more research could have done a better job.

The Rock Tumbler

We ended up getting a 3 pound capacity rock tumbler from Harbor Freight. A rather simple design that looks like it will last a good while. It will polish rocks up to about 2.5″. The key component, it seems, is the rock barrel, which is made of rubber. The main purpose of the rubber is to minimize the noise. Keep in mind that the tumbler will be on for weeks on end. It appears that the maintenance of the device will be simple. One needs to oil a few bearings and watch that the engine belt is in good repair. My only regret here is that I did not price shop a bit more as I could have saved about 25%.

Polishing Compounds

Thankfully, there were options shown once I had selected and put the tumbler into my on-line shopping cart. There are typically four stages to rock polishing, with each stage stepping up in the grit number… higher means a finer polish.

The Rocks are the Thing

This is where I will most likely regret the initial purchase… the rocks we got are really good rocks, but they are quite different from each other. A key talking point in every website that I go to is that the rocks should be similar in hardness to each other, as defined on the MOH’s scale. While I tried to separate the rocks into similar looking piles, honestly, I am not versed enough yet to be able to identify rock types and get them into close enough piles. If you attempt to polish hard and soft rocks together… well, let’s just say, the soft rocks are not gonna fair well. I did some additional shopping on-line tonight and found some sources of “rough” rock. At least our next attempts will contain all of a single type rock that should make getting the rest of the process down easier.

What Did We Learn Today?

We started our first batch of rocks yesterday. Choose a group of rocks that look like quartz, added the appropriate first grind material and filled the rock barrel to about 2/3 full of water and set the barrel on the tumbler to begin turning away. We were supposed to open the barrel after 12 hours to get rid of the gas build-up. When I opened the barrel this morning, about 18 hours into the cycle, I found that a significant amount of foam had formed. My initial impression was to add water to the mix… well, when referencing the tutorial noted above, it indicated that foam is a sign of too much water. Ahhh, the learning begins. We’ll let you know how this first batch turns out.

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