Tips for cleaning sterling silver jewelry?

October 28, 2006 3:12 PM

I've been cleaning some sterling silver necklaces with a jewelry polishing cloth. The necklaces now seem clean, but there is still a lot of black stuff coming off on the cloth, no matter how long I scrub the necklaces with it. Why is this?
posted by zembla3 to clothing, beauty, & fashion (8 comments total)

When you polish, you expose fresh silver to oxidizing atmosphere. If the particles of silver you are removing to the cloth are very, very small, they will oxidize pretty quickly, especially under the local heat produced by the very, very fine abrasives included in most polishing cloths. So, you can basically polish forever, if you're goal is to have a cloth not show black. It never will. Stop polishing as soon as your silver peices has the appropriate luster you are trying to achieve.
posted by paulsc at 3:34 PM on October 28, 2006

Piggybacking... If I clean my silver jewellery regularly, will it gradually become smaller and smaller? I know this is kind of silly, but it's why I've been procrastinating. It's all looking all tarnished and ucky.
posted by Savannah at 4:02 PM on October 28, 2006

Elemental silver is "Not attacked by water or atmospheric oxygen; [it is] blackened by ozone, by hyrogen sulfide, by sulfur." (Merck Index,12th ed. p.8652) Any tarnish on silver in an ordinary household situation is probably silver sulfide (AgS). According to John Emsley, author of The Elements, silver is "stable to water and oxygen, but attacked by sulfur compounds in air to form black sulfide layer" (2nd ed. p176).

When I polish chrome, which is also not oxidized in air at room temperature, the powder on a cloth or paper towel is also black, so I am inclined to say you are seeing very fine grains of silver on the cloth, which look black from some combination of the fineness of the particles and their geometry.
posted by jamjam at 4:28 PM on October 28, 2006

Savannah writes "Piggybacking... If I clean my silver jewellery regularly, will it gradually become smaller and smaller?"

Yes. If it's solid silver, however, this isn't much of a concern, as you're only taking off a very thin layer with each polish. If it's just silver-coated, however, it might just have a thin layer to start with, and repeated polishing might eventually reveal the base metal underneath.

There are chemical methods of polishing silver that work by turning the tarnish (silver oxide or silver sulfide) back into elemental silver. Here's one such method.
posted by mr_roboto at 4:35 PM on October 28, 2006 [4 favorites]

Ahhh ... that clears it up. Thanks guys.
posted by zembla3 at 4:48 PM on October 28, 2006

Silver sulfide is 2Ag1S. Sorry.
posted by jamjam at 4:57 PM on October 28, 2006

mr_roboto is correct. It should be noted, however, that the baking soda and boiling water method shouldn't be used if the jewelry in question incorporates pearls, turquoise, opals, or other soft stones. It can dissolve, crack, or otherwise ruin them. It can also leach out color from dyed stones. On plain sterling, though, it works great.
posted by Powerful Religious Baby at 5:38 PM on October 28, 2006

I just tried that--haven't had so much fun on a Saturday night since I was a single gal. I did only try it with pieces of jewellery that don't have coloured stones or pearls in them, and it worked like a hot damn! I can't wait to wear my stuff now that it looks so great.

Thanks!
posted by Savannah at 9:02 PM on October 28, 2006