One common question that gold prospectors have is about the best way to clean their placer gold.
Most of the time, gold nuggets that come out of the ground are not shiny and clean, but rather have a variety of “crud” that covers them. This is especially common in arid environments or areas where to gold has not been exposed to moving water.
Prospectors using metal detectors will often recover gold nuggets that are very dirty, and need to be cleaned in some way to improve their appearance. This is especially important if you intend to sell them to a mineral collector, but even if you intend to keep your gold, a bit of light cleaning will generally improve the overall beauty of the piece.
Popular Methods of Cleaning Gold
Cleaning gold nuggets is really not that difficult, and depending on the type and amount of material attached to the gold should make a difference on what cleaning method that you use. Some nuggets have just a light coating of dirt and grime that is easily cleaned with a light scrubbing, while others may require a soaking in some sort of chemical to break apart the grime that is attached to them.
I would recommend that you start cleaning your gold nuggets by simply scrubbing them with a little soapy water and a tooth brush. The vast majority of nuggets will clean up quite nicely using this method, and it is about as simple as it gets. You can also soak the gold in a mild vinegar solution for a few hours prior to scrubbing, which will help break up some of the more stubborn deposits that are attached to the nuggets.
Another simple cleaning method is to use a vial of salt and white vinegar. In a small container, add plenty of salt, and add vinegar, just enough that it covers your gold completely in the vial. Make sure you add plenty of salt so that there is a good accumulation of un-dissolved salt at the bottom of the vial. The vinegar helps break apart the grime attached to the nugget, and the abrasive nature of the salt scrubs and breaks apart the deposits as well. Simply shake the bottle for a few minutes and you will notice the vinegar will take on a stained color, indicating that dirt and grime are being released from the nugget.
Depending on how dirty your gold nugget is, you can do this step once or repeatedly, letting it soak in solution for several weeks. Shake the solution every few days.
If you are a serious prospector and find gold nuggets on a regular basis, a great investment to make is a simple hydrosonic cleaner, the kind that is used for cleaning gold jewelry. These do an excellent job breaking up dirt deposits attached to nuggets.
Ideas for Really Dirty Gold Nuggets
The above mention tactics are simple solutions that will work a lot of the time, but sometimes you will encounter gold nuggets that are coated with extremely hard deposits of caliche, dirty quartz, and other host material that is very difficult to remove. In this case, a harsher chemical will be required to clean them.
There are a few different household cleaners that will help remove these materials, if they are soaked long enough. Popular rust removers like CLR will do a great job, as well as other common acids. These do a great job, but care must be taken for safety reasons.
(I now recommend and use a product called Whink Rust Remover to clean up gold nuggets)
It is commonly written that hydrofluoric acid is a great way to clean nuggets, which it is. Unfortunately, it is also deadly, even in small doses. A few drops on a person’s skin can cause extreme burns and death. Please do not use it unless you are a trained professional! There are much safer methods to clean gold nuggets that are not so dangerous.
Best Option will Depend on the Gold
Cleaning gold nuggets is not difficult. Depending on the amount of dirt, grime, quartz, caliche, or other material attached to them will have an effect on how easily that they can be cleaned.
On most nuggets, a simple soapy scrub will clean them up quite nicely, while others may require a soak in some harsher chemicals to clean them up.
Have patience, as sometimes it takes a few weeks to complete the cleaning process on some of the dirtiest nuggets. Also keep in mind that sometimes cleaning a specimen can devalue it, specifically when dealing with quality pieces of gold in quartz.
I recommend using the simplest methods possible, and only use the harsher chemicals if the simpler methods don’t work.