Silver science

Standard

I received a Tiffany & Co. bracelet from the boyfriend this christmas. Other than the beautiful Tiffany blue box it came in, there was also a silver polishing cloth which set me thinking… Time for another science-y blog post!

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One touch and you can tell there’s something special  about this cloth. So what’s in this cloth? Why does silver need a special polishing cloth?

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But first, an introduction to Sterling Silver

Pure silver, the unprocessed element is soft and scratches easily. It has a brilliant shiny appearance but tarnishes very quickly. Therefore, most silver products are mixed with some other metal to make a silver alloy. Only silver with at least 99% natural silver is deemed pure.

Admiring every tiny detail on my new precious accessory, I spotted an engraving “AG925”. If you remember from science class, Ag is the chemical symbol for the element silver. The number stands for 92.5% because Sterling silver (which tiffany is famous for) is an alloy containing 92.5% pure silver and 7.5% of other metals, mainly copper. This enhances durability.

1_silver_periodic_table

Who’s taking away my shine

Sulphur and sulphur compounds (hydrogen sulphide) in our polluted air react with silver via a chemical reaction which forms silver sulfide Ag2S, a black substance. This discoloration is what we call tarnish. Silver tarnish may appear yellow, dull gray or even brownish black depending on how long it has been allowed to develop.

The tendency for silver to tarnish increases as its purity decreases. This is due to the tarnish of other metals in the alloy, from reactions with oxygen in the air. E.g. copper oxidizing to copper oxide

Did you know that ppl actually oxidize things ON PURPOSE?

During my research i came across many “how to” sites demonstrating techniques to give your jewellery an antique feel. “Tarnish can be viewed as a quality that denotes age and character of an object, such as a piece of antique sculpture.”

Fun fact: Today’s statue of liberty is only aqua-green due to copper tarnishing (copper carbonate) over the years! wow.

statue_of_liberty

So finally, what’s the deal with this silver polishing cloth?

Silver polishing cloth is a normal piece of soft cotton cloth impregnated with silver polish and anti-tarnish agent to clean and protect your pretty silver pieces. They should only be used on silver items. The Tiffany one retails at USD5 for the mini size.

Silver polishes typically contain an abrasive and work via mechanical action. Think of sandpaper, where the outermost surface is abraded, exposing a new shiny surface. Remember that silver scratches easily? A tiny bit of silver will be abraded away with this method, so sad!

Anti-tarnish agents on the otherhand, work chemically. In essence, it forms a transparent wax-like coating over silver to protect it from the environment, like a physical barrier.

Some home remedies to remove silver tarnish involve a metal like aluminium (Al), which has a stronger affinity for sulphur than silver does. Therefore, a chemical reaction can be utilised to displace the silver (Ag) from the black silver sulphide (Ag2S) tarnish, forming aluninium sulphide (Al2S3) instead, to free the shiny silver metal beneath. Vaguely recall this as substitution? Here are the equations for those who get it.

2 Ag(s) + H2S(g) → Ag2S(s) + H2(g)

3 Ag2S(s) + 2 Al(s) → 6 Ag(s) + Al2S3(s)

Now something funny to wash away the seriousness …

i-told-popeye-a-joke-about-silver-he-went-agagagagag

There are several types of anti-tarnish agents in the market, each brand hailing their own as a “unique patented formula”.

Obviously, do NOT ever wash this cloth! As the chemicals impregnated in it would  be washed away.

Taking care of Silver

As hot, humid climate speeds up tarnishing, its especially important to take good care of your valuable silver in sunny Singapore. No link, but here’s us on a sunny day.

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Below are some tips I’ve gathered to care for that new piece of bling (disclaimer: no idea how true they are).

– Wear your sterling silver pieces often! As oils in your skin polish the silver for you

– Allow any lotions/perfumes/hair products to be fully absorbed into your skin/hair before putting on your bling

– Wipe any residue off before storing, to prevent enhancing the tarnishing process

– Store silver in an airtight container such as a resealable plastic bag, cloth bag or an airtight jewellery box (apparently there are jewellery cases out there that contain sulphur which will interact and tarnish silver, beware!)

If all this is too much of a hassle, you might wanna invest in platinum or white-gold instead.

Argentium Sterling Silver

A relatively new material in the market is Argentium sterling silver, which is said to be highly tarnish-resistant. It comprises 92.5% silver, about 5.9% copper and 1.6% germanium. As it still contains at least 92.5% pure silver, it is still referred to as sterling silver.

ArgentiumSilver

The magic of this silver alloy stems from germanium combining with elements in the air to form a clear compound which coats the product. This prevents sulphur in the air from coming in direct contact with the silver and thereby prevents the formation of a dark tarnish. When it does tarnish eventually, a light yellow discoloration is usually the case, which can be easily removed with soap and water.

Advice from Tiffany & Co. 

“Sterling silver is a precious metal and may require cleaning from time to time. Using a small amount of Tiffany’s silver jewelry cleaner on a soft cloth, gently rub the silver several times. Then rinse the silver thoroughly in warm water and carefully dry. This will remove the tarnish and dullness, keeping your sterling silver like new. Please note: chlorine and bleach accelerate tarnishing and should be avoided.”

And after all that, best part right here… YAYYYYY

Silver polishing services are available for sterling silver jewelry, flatware and hollowware items manufactured by Tiffany & Co.

Ending this post off with Silver from 90210. Love her!

cw-90210-prt-jstroup_011994-867533-325x434

Here are some of the useful sites I used.

http://www.overstock.com/guides/silver-types-fact-sheet              http://www.accessoriesonline.co.uk/jewellery-care/  http://www.silvermagpies.com/2011/10/19/silver-tarnish/  http://atelierworkroom.blogspot.sg/2009/03/silver-polishing-cloth.html  http://www.compoundchem.com/2013/12/16/removing-tarnish-silver/

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