Boneblogger: Science and the outdoors

Exploring the natural world

How To Polish Stones By Hand

Ever asked yourself how it was that people two hundred years ago used to get their rocks and gems such as clear quartz to be so clear and perfect when they didn’t have rock tumblers available? It’s not like they could toss a few rocks into the sea and then sit back for a few decades waiting for for the water and sand to do its thing.

No, they did it all by hand. And if you’re interested in giving it a try, you might it to be a rewarding – if somewhat labor-intensive – undertaking.

So how exactly does one go about polishing rocks by hand?

Ideally, you should start with a soft stone – something that registers 3-4 on the Mohs hardness scale. This isn’t an absolute rule – you can work on harder stones, but the time and energy you have to expend is going to rise considerably. Start with something like onyx, or perhaps a calcite or dolomite.

Don some safety goggles, gloves and even an air mask. Rock dust is nothing to sneeze at, if you’ll pardon the pun. Using a small hammer and chisel, remove any chunks from the stone that stand in the way of its ideal form. Once the larger ones are gone, briskly grind the stone against some concrete. This will wear away the smaller protuberances.

When you’re pleased with the general size, get yourself some 50 grain sandpaper and begin to work over the entire stone. Concentrate on consistency – again, what you’re doing here is slowly grinding the stone into a final shape.

Once it’s there, you can start working with a finer grade sandpaper – say 150 grain. Again, simply get comfortable and work away at the stone. You are soothing the marks that were left by the concrete and the 50 grain sandpaper. It’s about this stage that your stone will start to resemble something finer and prettier than you see out in the field.

At this point you can move up to a finer grade of sandpaper – depending on the rock, anywhere from 300 to 600. This is the refinement stage. Any remaining blemishes are going to be smoothed away.

The final stage is working with ultra fine sandpaper – or even better, a soft cloth like denim. Slowly clean and rub the stone. Let it air dry, then apply a commercial stone polish – you can find this at just about any good hobby store that knows a thing or two about rock hounds.

You’ll notice that the final result looks a bit rougher than the stones you get through your tumbler. But take heart – you’ve worked really hard. You might find that a stone polished by hand means a bit more to you now!

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