Burnishing - the least destructive polish
When applied to jewellery, burnishing is taking a metal object harder than the precious metal and rubbing them together with force to obtain/restore a polished surface to the precious metal.
Scratches remove some precious metal but to a large extent they are formed by displacing the metal on the surface rather than removal. You can push those scratches back in and that is the plastic deformation referred to in the above definition.
As the surface of the precious metal is burnished its plasticity reduces. It hardens making it more durable for the future.
With a new piece of jewellery, despite it being scratch free, I burnish it to make the surface more durable.
So why is burnishing not normally done?
The main reason is that this method takes more time and skill, especially with detailed pieces than the alternative method which is to file, emery and polish those scratches out. The public in general demands cheap and quick.
Disadvantages of the alternative - file, emery and polish
Thins the piece during the filing and emery (removal) of all precious metal down to the lowest point of the scratches
the surface does not receive the hardening benefit of burnishing
Something to think about
Most of the jewellery sold in Australia is mass produced and/or imported. Most of the resellers of jewellery in Australia outsource their repair work.
The person to whom the servicing of your jewellery is entrusted to gets to keep whatever precious metal comes off your jewellery during a file emery and polish. Those filings and dust are part of their income, why would they want to burnish your ring?
Time to burnish this ring
In the video below I have burnished a small section of the ring. Hopefully the video is clear enough that you can see how the metal is pushed back into a flat and polished surface. I am still learning how to use this new camera and the auto focus pulses a bit in the video sorry :(
You will also notice in the video that jewellers (me/I) struggle to keep their hands clean, especially their finger nails due to the polishing compounds. Polishing jewellery can get dirty.
Nearly finished - the final polish
You can see that the scratches have been flattened back into the ring in the photo above. The final step is to give it a very slight buff on the polishing machine.
It is important to remember that the polishing wheels and cutting compounds do remove metal from the surface. This is why it is important to not over polish jewellery as it thins the piece out and removes detail when present.
In Summary - the benefits of burnishing
accurate (with detailed pieces) burnishing avoids your jewellery from being excessively thinned out and detail lost from filing, emerying and polishing
hardens the surface making it more resistant to future scratches
reduces the need for polishing with cutting compounds (which thins your jewellery) to a minimum
So how much do you charge to burnish David?
I do this for free for every piece I make, again at the one month checkup (free) and every time time I give a piece I made a free clean.
I stopped servicing jewellery made by others a long time ago now. I created this article so that my customers could know why I go on so much about burnishing.
I hope that they also understand better why check ups and cleans take time to do properly.