Baking soda, hot water, and aluminum will remove tarnish from silver without the faintest application of elbow grease.
Which is useful for, in this case, a fragile silver pendant I had thought to have been lost for good, and had missed very greatly.
How it works:
The aluminum produces ionized particles when heated up with the baking soda.
The aluminum ionized particles bond with the crap that's bound to the silver, much more readily than it binds to the silver.
What you use: just a sheet of aluminum foil in the bottom of a pot; sprinkle on the baking soda. heat water, insert silver, remove silver.
You can just use Very Hot Water from the tap; it takes longer (just soak it for a half-hour). The boiling method is nigh-instantaneous.
Result: a pot full of undrinkable water, and SHININGLY clean silver.
This data brought to me by
sinick, who also supplied a kid's science experiement which explains things. PDF file, in case you are a person who objects to such.
Which is useful for, in this case, a fragile silver pendant I had thought to have been lost for good, and had missed very greatly.
How it works:
The aluminum produces ionized particles when heated up with the baking soda.
The aluminum ionized particles bond with the crap that's bound to the silver, much more readily than it binds to the silver.
What you use: just a sheet of aluminum foil in the bottom of a pot; sprinkle on the baking soda. heat water, insert silver, remove silver.
You can just use Very Hot Water from the tap; it takes longer (just soak it for a half-hour). The boiling method is nigh-instantaneous.
Result: a pot full of undrinkable water, and SHININGLY clean silver.
This data brought to me by
sinick, who also supplied a kid's science experiement which explains things. PDF file, in case you are a person who objects to such.
I've got a bunch of silver earrings I need to clean...
Details for the detail oriented:
The aluminum produces ionized particles when heated up with the baking soda.
The aluminum ionized particles bond with the crap that's bound to the silver, much more readily than it binds to the silver.
What you use: just a sheet of aluminum foil in the bottom of a pot; sprinkle on the baking soda. heat water, insert silver, remove silver.
You can just use Very Hot Water from the tap; it takes longer (just soak it overnight). The boiling method is nigh-instantaneous.
Result: a pot full of undrinkable water, and SHININGLY clean silver.
Re: Details for the detail oriented:
Re: Details for the detail oriented:
The really great part of the electrolytic method is it's the only way to clean silver that actually leaves you with the original amount of silver you had before it was ever tarnished. All the other methods of cleaning silver (cloths, pastes etc.) work by physically scrubbing off the tarnish layer, which of course means you lose silver, and in the case of sculpted/figured items, abrade the surface details irreversibly.
I'm thrilled you liked the little recipe! Times like this it's nice to be a chem geek / jewellery/lapidary freak.
Good new icon.
More details
The aluminum produces ionized particles when heated up with the baking soda.
The aluminum ionized particles bond with the crap that's bound to the silver, much more readily than it binds to the silver.
What you use: just a sheet of aluminum foil in the bottom of a pot; sprinkle on the baking soda. heat water, insert silver, remove silver.
You can just use Very Hot Water from the tap; it takes longer (just soak it for a half-hour or so). The boiling method is nigh-instantaneous.
Result: a pot full of undrinkable water, and SHININGLY clean silver.
Mind you don't leave your pendant in there too long; it'll go the way of all good electrodes and dissolve.
The silver will eventually bond to the aluminum if you do this too long, yes: the first thing to bond, though, is the non-silver portion of the compound that is tarnished silver.
To help prevent tarnish recurring:
Don't store silver near materials that exude sulphur or salt (latex, natural tortoiseshell etc). Unfortunately, skin is pretty bad for both these compounds.
Best stored in a dark place, in an airtight bag with the air sucked out. If you're extra picky/determined to keep tarnish at bay, add a sachet of activated charcoal into the airtight bag (you can get it from aquarium suppliers: they use it for tank filters). The charcoal absorbs sulphur compounds, but it won't work indefinitely of course. Change the sachet annually.
Eureka!
Mostly sulfides and chlorides and perhaps nitrates, I imagine, are what you're getting rid of. AgCl (Silver Chloride) is largely insoluble in water and definitely is the right color. AgNO3 (silver nitrate) also has the right look about it, though it's much more soluble in water.
As for the use of hot water, it's simple kinetics. It just makes the red-ox reaction (Al -> Al 3+ while Ag+ -> Ag) go scads faster.
The bicarbonate (HCO3-, or baking soda) isn't actually the cleaning agent in this case, either (though in many, it is). Bicarbonate is a very common catalyst for aqueous electrolysis reactions (water being split into hydrogen and oxygen is made 1000-fold faster with some bicarbonate in the water, for example).
Chem-geeking... It's been a while.
The core reaction is:
3 Ag2S(s) + 2 Al(s)+ 3 H2O(l) -> 6 Ag(s) + Al2O3(s) + 3 H2S(aq)
(silver sulphide + aluminium + water -> silver + aluminium oxide aka bauxite + hydrogen sulphide aka rotten egg gas)
Fortunately, the baking soda reacts with the rotten egg gas, producing nice odorless nontoxic carbon dioxide.
3 NaHCO3(aq) + 3 H2S(aq) -> 3 NaHS(aq)+3 H2O(l)+ 3 CO2(g)
(baking soda + rotten egg gas -> sodium hydrosulphide + water + carbon dioxide)
Personally, I'd _not_ recommend this method with stones like opals or other microfractured/hydrated stones, stones with large flaws (surface fissures visible to the naked eye), inclusive stones such as rutilated quartz, and with organic gemstones (pearl, coral, amber, jet).