Tripped Up Tuesdays: Heartbroken!

Although the household baking soda solution and aluminum foil method is one of the safest ways to clean silver jewelry, things get trickier if there are gemstones involved.  Most gemstones do fine in baking soda and water, but the method should be avoided for jewelry set with corals.  For opals and turquoise, there seems to be some controversy over whether saltwater baths are safe with some saying yes and others, no.  I don’t own any opals, so that’s not even on the table, but I do put turquoise in baking soda solutions.  It does fine, but I generally need to re-polish it when I am done.

Today’s piece is a near-antique, heart shaped Chinese Export pendant with, as you can see below, a delicately traced ink painting on ox bone.  What idiot, you might ask, would put *that* in a baking soda solution????  Well . . . given this is a blog about the stupid stuff I do, who do you think? 

I too was worried about the painting’s integrity, but the silver was incredibly tarnished. With all that silver mesh, hand polishing just wasn’t going to clean it well.  I know there are people out there who like their silver well-patinaed, but I’m not one of them.  I decided to carefully place the pendant into a warm (not hot) baking soda solution to a level just below the bone.  Unfortunately, thanks to the miracle of capillary action, all of the solution ended up on top of the bone painting anyway. 

Only, it looked great when I was done!  I mean really great.  The solution had lifted off approximately 100 years of grime and slime, and suddenly the painting looked vibrant and fresh.  Furthermore, by lifting all that grime, the soda solution had uncovered red accents in the painting that were breathtaking.

So  I did it again.  Because all the solution had ended up on top of the painting the first time around, the silver was still tarnished.  Therefore, this time, I didn’t bother with putting in a little bit of water.  I completely covered the pendant and let ‘er rip.  10 minutes later, I got what you see below.  Much paint, including all of the red, had been lifted away.  The ink that was left diffused out of the painting and settled into grooves in the bone.  In a word, I ruined the pendant.

Next time I will either remove the painting first or stick to hand polishing after all.

Tripped-Up Tuesdays: Holy Reverse Redox, Batman! How not to use baking soda and aluminum to remove tarnish from silver

With a few exceptions, nothing beats the safety of a bicarbonate/aluminum foil/water bath for removing tarnish from silver.  If you aren't careful however, things can go very wrong:

It started innocently enough:

Several objects covered with baking soda, ready for the hot water bath.

But within moments, this happened:

Notice that several of these sterling beads have actually turned black, not shiny silver!
It turns out there were several potential culprits:

The two Art Deco "Bubble" Necklaces on the left were strung on nickle chain, not silver plate as I had been told by the vendor, and a nickle safety chain had been attached to the amethyst bracelet on the right. In addition, a fourth necklace had been strung on uncoated metal wire of unknown type and crimped with what appeared to be zinc metal.

Tarnish is caused when hydrogen sulfide reacts with surface silver to form silver sulfide. This process can be reversed in a classic redox electrochemical reaction by placing silver (the cathode) in a salt water bath (the baking soda dissolved in water) with a metal that has more affinity for sulfur than silver has (here, aluminum --the anode).  The two metals need to be in contact with one another. The process messed up here because I inadvertently placed a tarnished metal into the bath that actually had less affinity for sulfur than did the silver.  The problem was remedied easily enough--I just needed to repeat my saltwater bath making sure that nothing other than silver and aluminum were in the chemical mix.  I have also started to use this:

A neodymium magnet can be used to detect any unexpected magnetic metals in your jewelry (primarily nickel).  I also now create separate aluminum "boats" for each piece of jewelry so that if the redox reaction does go wrong, it will at least be limited to a single piece.