Cleaning Gold Specimens - Step By Step Methods

[Glenn in CO]

PART FIVE:

The gold specimens have been soaking in the Whink solution for around two weeks. To speed up the process I will be using baking soda and the steam cleaner. You will use a large amount of baking soda. I usually buy it at Wal-Mart, the last bag I bought was a 12 lb. bag and cost around $9.00.

The baking soda is used to neutralize the acid and helps remove the host rock. The gold specimens that are being cleaned have shale as a host rock with limonite and other small amount of minerals that might be included. Shale and limonite is porous and soaking the gold specimens in the Whink solution for a period of time allows some of it to be absorb. There is no precise amount of baking soda I use for this next step. I normally fill about a half inch in a bottom of a container and mix it with water. I then take a gold specimen and drop it in the baking soda and then there will be a intense reaction which causes the shale, limonite and other minerals to break away from the gold. Depending on how much of the Whink solution was absorbed you will have a reaction with the baking soda for a little to a longer period of time. I usually change out the baking soda mixed water two to three times until there is no visible reaction with the gold specimen.

The next step is using a steam cleaner and applying steam to the gold specimen. The steam cleaner generates about 212 degrees of steam and around 45 lbs of pressure. Using the steam cleaner removes some of the host rock and other minerals that has been weakened by the Whink solution. The results can differ from one gold specimen to another. If the result is not what you wanting to achieve, then the next step is another round soaking in Whink or acid of your choice and then repeat the process with the baking soda and steam cleaner. Also carefully using dental picks to help remove the host rock and other minerals can be used, but use them with extreme caution.

Using Whink, baking soda and steam cleaner on these gold specimens especially the wire gold specimens I can achieve good results with minimal loss of gold and structure to gold specimen. Here are the before (specimens that were soaking in Whink) and after (using baking soda and steam cleaner) pictures:

Gold specimens after soaking in Whink solution.

Gold specimens after using baking soda and steam cleaner.

Area that is circled is the loss of gold from the cleaning process so far. Specimen D needs no further cleaning.

 

Part six I will show the results of another round of soaking in the Whink solution and using the baking soda and steam cleaner.

 

 

[Glenn in CO]

PART SIX:

Here are the results of another round of soaking in the Whink solution and using baking soda and steam cleaner.

Specimen A still has a lot of the host rock to remove, Specimen B has some host rock embedded in between the wires of gold, Specimen C has a tiny amount which the photograph does not show and Specimen D needs no further cleaning.

At this point going forward using the Whink solution is not going to have the results I like to achieve. Next step I will use Muriatic acid with another round of baking soda and steam cleaner.

I will post photographs of the final results of the last cleaning.

[jasong]

Golden fleece, literally.  Nice stuff to see emerge.

[Glenn in CO]

PART SEVEN:

This is the final step of the cleaning process on these gold specimens. After soaking the gold specimens in Muriatic acid a few days I then place them in a solution of baking soda and water. There is an aggressive reaction for a short period of time to the gold specimens causing more of the host rock to be removed. Then I rinse each gold specimen in water. I then have four containers in which two have Muriatic acid, one with baking soda and one with water. I then take each gold specimen and place it in the first container of Muriatic acid, then in the second container of Muriatic acid, then in the solution of baking soda and the rinse each specimen again in water. I repeat this process several times. The reason I place each gold specimen two times in the Muriatic acid is because the Muriatic acid becomes weakened when I rinse the gold specimens in water. I then soak the gold specimens in a solution of baking soda for a couple days and the rinse them in water. The final step is to apply steam to each gold specimen for additional cleaning.

During the entire cleaning process there is some loss of gold from some of the gold specimens and it is a judgement call on how far one should continue the cleaning process. That judgement call can be great or it can be disastrous.

Pictured below is the loss of gold from the cleaning process:

I will post pictures in another thread of the gold specimens before and after the were cleaned.