How to clean native silver?

Does anybody know how to clean native silver on calcite without damaging the specimen?

Try putting about 1/2 cup of baking soda into 2 cups of water. Next, cover the bottom of a pot with aluminum foil. add water and boil. Next, add the silver and several (at least 5) small 1-inch diameter balls of aluminum foil. Keep silver in boiling water for 10-15 minutes... Always works great for me!

Thanks David!
As soon as it is possible I will try your method.
Another question : must I use distilled water?

I find that distilled water works best. I HIGHLY RECCOMEND USING THIS TECHNIQUE ON A SMALL SACRAFICIAL PIECE OF THE SPECIMEN AT HAND. Although this method always works for me, It may not work to your satisfaction. If the sacraficial piece is not what you want it to be like, I'll try to think of another way.

Hello,

I assume that you mean removing the tarnish, instead of simply cleaning soil from the specimen. The method I will outline is similar to that of David above; like his, it works electrolytically. You can use it to remove a good percentage of the tarnish on silver specimens and I don't think it will harm calcite. Best results are obtained by observing the specimen during treatment and pulling it out when enough tarnish has been removed to improve the appearence. Some tarnish can be quite aesthetic. You should also carefully consider whether the tarnish is actually unsightly before you risk a specimen. Try the treatment for a minute or two and then repeat until you are satisfied. It is best to err on the side of conservatism, rather than ruin a piece.

Here is the method: Place a flat piece of aluminum at the bottom of a sauce pan. A nice short length of aluminum flat bar is best, but any solid flat piece of aluminum will work. Fill the pan part way with enough distilled water to cover the specimen when it is resting on the aluminum. Create a saturated solution by heating up the water until it is warm to hot (not boiling) and adding baking soda (sodium bicarbonate) and table salt (sodium chloride) in equal amounts until you can dissolve no more. A little excess undissolved salt or soda does not seem to harm anything. Place the silver specimen on the aluminum so that the silver metal makes electrical contact with the aluminum. Wait and watch, keeping the solution below boiling in temperature.

This method has worked for me.
Best Regards,
Bob

Yesterday I cleaned the two pieces of native silver that I have with the method of Bob but I did not add sodium chloride.
It worked very well, in about 2 minutes the tarnish go out without damaging the calcite and the two pieces were very good.
I thanks David and Bob for their help!

Federico,

If you can find it, a silver cleaner called "TarnX" works very well to clean silver and copper, without damaging the clacite or other minerals......

You'd better watch out when using Tarn-X with calcite! The active ingredient in Tarn-X is acidified thiourea, a potent reducing agent. While thiourea is probably one of the best ways I know of to remove tarnish and corrosion from copper and silver, Tarn-X contains acids to lower the pH of the solution. These acids will rapidly attack carbonates such as calcite and malachite. I've used straight thiourea to clean copper and silver electronic parts with success. One of the more interesting cleaning methods I've tried involves placing the metal to be cleaned in a solution of thiourea and then adding an equal amount of 30% hydrogen peroxide. After a few seconds, the mixed solutions will react violently enough to spew boiling liquid out of the container. (This is best done outside, over a catch basin.) After the reaction quiets down, the metal will have acquired a mirror-like polish. This method is a variation of an old metal finisher's process known as bombing. The original process used sodium or potassium cyanide instead of the much safer thiourea. Definitely not recommended, even if you could get the cyanide. 30% hydrogen peroxide can be gotten at any Home Depot store, if you know what to look for. This stuff is extremely nasty and will leave painful bleached spots on any exposed skin it happens to contact.

Franklin Roberts
Austin, Texas

I also thanks 'CaptPaul' and 'Franklin Roberts' for the suggestion but I cleaned the pieces of Native Silver with the method of 'Robert Meyer' and I am very satisfied of the result

Regards

Federico

Would either the electrolytic method involving the silver-aluminum cell or the use of "TarnX" be usable on a matrix specimen of native silver dendrites on native arsenic? The use of aluminum wads circulatinjg by boiling water might allow the former to work here.I would appreciate coments from users of both methods.

Thanks and Best Regards,
Mel Judy

Bob, I found a 19.92 lb silver nugget in Az.. Not knowing better I tryed to clean it with mueratic acid. It didn't take the tarnish off. I hope I didn't ruin it. Do you think it is to late . Thanks Doug

Hi!

Does the method explained by Robert Meyer works for cleaning pyrargyrite?

Thanks
Ignacio

Ignacio, The electrolytic methods probably won't work on pyrargyrite because sulphosalts do not conduct electricity. The native slver works because of its conductivity.

Doug when you used the muratic acid did it turn a dark shade of gray?

warning on using tarn x on native silver!
some silvers become "addicted to it" and will tarnish more often after being treated just once!
beware!

Just a note for keeping silver specimens bright. Enclose it in a plastic or glass box with a piece of 3M Anti-Tarnish paper enclosed.

I metal detect on the weekends for fun and think I may have found a silver nugget but not sure so what's the beat way to tell.

One consideration for the method of cleaning silver, it that the electrolytic aluminum technique reduces the tarnish depositing the silver back on the specimen. Other methods of tarnish removal actually removes the tarnish (silver sulfide) taking the combined silver with it . This means that repeated cleanings with non-electrolytic methods will gradually reduce the weight of silver in the specimen over time.

Be careful with thiourea. This stuff is highly mutagenic.

Have another question for this thread. Ran into some nice micro silver crystals in the Keweenaw of Michigan. Some are very sharp and lustrous in prehnite vugs but others were at or near the surface of the rock and look dull (tarnished?). Would appreciate recommendations on cleaning these crystals. Preserving calcite is not an issue (in fact I'm acid etching calcite off some of the trimmed rock fragments in attempt to discover more crystals, some of the vugs and fissues are calcite filled). However, a few silver cystals are associated with copper wires. Another potential problem in cleaning these specimens is loss of the crystals, some are loosely attached in the vugs. In fact one silver crystal disappeared during handling of the material (disappointing as that one had an associated tangle of copper wires!).

Thanks,

George